SCIENCE | Class 10 | Question Bank 2026 Solutions; Chapter 6: Life Processes | SEBA (Board of Secondary Education Assam)
A. MCQs.
**(i) Emulsification of fat molecule is carried out by-**
**Answer:** (c) Bile salts
*(Bile salts emulsify fats, increasing the surface area for enzyme action.)*
**(ii) Anaerobic respiration occurs in-**
**Answer:** (d) Cytoplasm
*(Anaerobic respiration (glycolysis) occurs in the cytoplasm, while aerobic respiration happens in mitochondria.)*
**(iii) The enzyme which converts starch to simple sugar is-**
**Answer:** (a) amylase
*(Amylase breaks down starch into maltose and other simple sugars.)*
**(iv) The process fulfilling carbon and energy requirements of autotrophic organisms is-**
**Answer:** (a) Photosynthesis
*(Photosynthesis converts CO₂ and light into glucose and energy.)*
**(v) The part of the brain responsible for hunger and thirst is-**
**Answer:** (d) hypothalamus
*(The hypothalamus regulates homeostasis, including hunger and thirst.)*
**(vi) The enzyme contained by our saliva is called-**
**Answer:** (i) amylase
*(Salivary amylase initiates starch digestion in the mouth.)*
**(vi) Sphygmomanometer measures ______.**
**Answer: (i) Blood pressure**
- **Explanation**: A sphygmomanometer uses an inflatable cuff and a pressure gauge to measure arterial blood pressure.
- **Why not others?**:
- (ii) O₂ levels are measured using a pulse oximeter.
- (iii) Blood sugar is tested with glucometers.
- (iv) Urea levels require blood/urine tests.
**(viii) Glucose → Pyruvate occurs in ______.**
**Answer: (a) Cell cytoplasm**
- **Glycolysis**: This anaerobic process breaks glucose into pyruvate. Mitochondria are not involved here.
- **Mitochondria** later process pyruvate in the Krebs cycle (aerobic respiration).
**(ix) Energy currency of cells is ______.**
**Answer: (c) ATP**
- **ATP (Adenosine Triphosphate)**: Stores energy in its phosphate bonds. When hydrolyzed to ADP, energy is released for cellular work.
- **ADP/AMP**: Lower-energy molecules; they are recycled back to ATP.
**(x) Xylem transports ______.**
**Answer: (a) Transportation of water**
- **Xylem**: Dead, hollow cells form tubes to move water/minerals upward (roots → leaves).
- **Phloem** (not listed) transports food (sucrose).
**(xi) Endothermic reactions use ______.**
**Answer: (c) ATP**
- **ATP provides energy**: Endothermic (energy-absorbing) reactions, like protein synthesis or active transport, require ATP hydrolysis.
**(xii) Amoeba reproduces via ______.**
**Answer: (a) Binary fission**
- **Process**: The cell splits into two identical daughter cells.
- **Multiple fission** occurs in Plasmodium (malaria parasite).
**(xiii) Pyruvate breakdown occurs in ______.**
**Answer: (b) Mitochondria**
- **Krebs Cycle & ETC**: Pyruvate is oxidized to CO₂ and H₂O, releasing ATP in mitochondria. Cytoplasm only handles glycolysis.
**(xiv) Kidneys are part of ______.**
**Answer: (a) Excretion**
- **Function**: Filter blood to remove urea, excess salts, and water as urine.
**(xv) Normal systolic pressure is ______.**
**Answer: (a) 120 mm Hg**
- **Systolic**: Pressure when the heart contracts. Diastolic (resting pressure) is ~80 mm Hg.
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**Fill in the Gap (Expanded):**
**(a) The process fulfilling carbon/energy needs and storing energy is ______.**
**Answer: Photosynthesis**
- **Equation**:
6CO_2 + 6H_2O rightarrow{Sunlight} C_6H_{12}O_6 + 6O_2
- **Stored Energy**: Glucose (used in respiration) and starch (long-term storage).
B.**Essay Questions (Detailed Explanations):**
**1. Release of Energy from Glucose**
1. **Glycolysis (Cytoplasm)**:
- Glucose (6C) → 2 Pyruvate (3C) + 2 ATP.
- Anaerobic; no oxygen required.
2. **Krebs Cycle (Mitochondria)**:
- Pyruvate → Acetyl-CoA → CO₂ + 2 ATP + NADH/FADH₂.
3. **Electron Transport Chain (Mitochondria)**:
- NADH/FADH₂ donate electrons → 34 ATP via oxidative phosphorylation.
4. **Anaerobic Pathways**:
- **Fermentation**: Pyruvate → Lactate (animals) or Ethanol + CO₂ (yeast).
**2. Transport in Plants**
- **Xylem**:
- **Structure**: Dead tracheids and vessels.
- **Mechanism**:
- **Transpiration Pull**: Water evaporates from stomata → creates suction.
- **Root Pressure**: Active ion uptake pushes water upward.
- **Phloem**:
- **Structure**: Living sieve tubes + companion cells.
- **Translocation**: Sucrose moves from source (leaves) to sink (roots/fruits) via active transport.
**3. Blood Flow Through the Heart**
1. **Deoxygenated Blood**:
- Body → **Right Atrium** (via vena cava) → **Right Ventricle** → Lungs (via pulmonary artery).
2. **Oxygenated Blood**:
- Lungs → **Left Atrium** (via pulmonary veins) → **Left Ventricle** → Aorta → Body.
- **Valves**: Tricuspid (RA/RV), Bicuspid/Mitral (LA/LV), Semilunar (aorta/pulmonary artery).
**4. Digestion in Alimentary Canal**
- **Mouth**:
- **Mechanical**: Chewing (teeth).
- **Chemical**: Salivary amylase breaks starch → maltose.
- **Stomach**:
- **HCl**: Kills bacteria, activates pepsinogen → pepsin.
- **Pepsin**: Digests proteins → peptides.
- **Small Intestine**:
- **Bile (Liver)**: Emulsifies fats.
- **Pancreatic Enzymes**: Trypsin (proteins), Lipase (fats), Amylase (carbs).
- **Villi**: Absorb nutrients into blood.
- **Large Intestine**: Absorbs water; forms feces.
**5. Breathing Mechanism & Rate Differences**
- **Mechanism**:
- **Inhalation**: Diaphragm contracts (flattens), intercostal muscles lift ribs → volume ↑ → air rushes in.
- **Exhalation**: Diaphragm relaxes (domes), ribs drop → volume ↓ → air pushed out.
- **Aquatic vs. Terrestrial**:
- Water holds <1% oxygen vs. 21% in air.
- Gills require constant water flow; lungs are more efficient.
**6. Photosynthesis**
- **Steps**:
1. **Light Reactions (Thylakoid)**:
- Chlorophyll absorbs light → splits H₂O → O₂ released.
- Produces ATP & NADPH.
2. **Calvin Cycle (Stroma)**:
- Uses ATP/NADPH to fix CO₂ into glucose.
- **CO₂ Absorption**: Stomata (leaf pores) open to take in CO₂.
*7. Excretory System & Urine Formation**
- **Parts**: Kidneys (nephrons), ureters, bladder, urethra.
- **Urine Formation**:
1. **Filtration (Glomerulus)**: Blood filtered → filtrate (water, glucose, urea).
2. **Reabsorption (Tubules)**: 99% glucose/water reabsorbed.
3. **Secretion**: Excess ions/toxins added → urine.
**8. Plant Transport System**
- **Components**:
- **Xylem**: Transpiration-driven water transport.
- **Phloem**: Energy-dependent food transport.
- **Transpiration Role**: Creates negative pressure to pull water upward.
9. Respiratory Pigment**
- **Hemoglobin**:
- In red blood cells; binds O₂ in lungs → transports to tissues.
- Also carries CO₂ (20%) back to lungs.
*10. Human Heart Circulation**
- **Diagram Notes**:
- Label chambers (atria/ventricles), major vessels (aorta, pulmonary artery/vein).
- Arrows show deoxygenated (blue) → lungs → oxygenated (red) → body.
**11. Photosynthesis (Advanced)**
- **Light-Dependent**:
- **Photosystem II**: Splits H₂O → O₂.
- **Photosystem I**: Produces NADPH.
- **CO₂ Uptake**: Stomatal regulation; CAM plants absorb CO₂ at night.
**12. Leaf Cross-Section**
- **Layers**:
1. **Cuticle**: Waxy layer (prevents water loss).
2. **Epidermis**: Protective layer.
3. **Palisade Mesophyll**: Photosynthesis site.
4. **Spongy Mesophyll**: Gas exchange.
5. **Stomata**: Guard cells regulate opening.
**13. Green Dots in Leaves**
- **Chloroplasts**:
- Contain chlorophyll; trap light energy.
- Site of photosynthesis (thylakoid stacks).
**14. Biological Catalysts**
- **Enzymes**:
- **Examples**: Amylase (starch → sugar), Pepsin (proteins → peptides).
- **Roles**: Speed up digestion, DNA replication, ATP synthesis.
- **Stomach HCl**:
- Denatures proteins, activates pepsinogen, kills pathogens.
*15. Transport in Xylem vs. Phloem**
- **Xylem**:
- Unidirectional (roots → leaves).
- Passive (transpiration pull).
- **Phloem**:
- Bidirectional (source to sink).
- Active (requires ATP for loading/unloading sucrose).
*16. Amoeba’s Feeding Process**
- **Phagocytosis**:
1. **Pseudopodia** extend around food (e.g., bacteria).
2. **Food vacuole** forms → fuses with lysosome.
3. Enzymes digest food → nutrients absorbed.
4. Waste expelled via exocytosis.
**17. What are the biological catalysts? What is their function?**
**Answer:**
Biological catalysts are **enzymes**. They are protein molecules that accelerate chemical reactions in living organisms without being consumed. Their primary function is to lower the activation energy required for reactions, enabling processes like digestion, metabolism, and DNA synthesis to occur efficiently at body temperature.
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*18. Name the respiratory pigment present in our blood and state its function.**
**Answer:**
The respiratory pigment is **hemoglobin**, found in red blood cells. It binds with oxygen in the lungs to form oxyhemoglobin, transporting oxygen to tissues. Hemoglobin also aids in carrying a small portion of carbon dioxide (as carbaminohemoglobin) back to the lungs for exhalation.
**19. Why do organisms require food? In what form and where do the food substances get stored? How is glucose oxidized?**
**Answer:**
Organisms require food for **energy**, **growth**, and **repair**. Excess food is stored as:
- **Glycogen** in the liver and muscles.
- **Fats** in adipose tissue.
Glucose is oxidized through:
1. **Aerobic respiration** (with oxygen): Produces CO₂, H₂O, and 36-38 ATP (in mitochondria).
2. **Anaerobic respiration** (without oxygen):
- In muscles: Produces lactic acid (2 ATP).
- In yeast: Produces ethanol and CO₂ (2 ATP).
---
**20. Draw a labelled diagram of the human heart and describe blood flow. State the importance of valves.**
**Answer:**
**Blood Flow:**
1. Deoxygenated blood enters the **right atrium** → flows to **right ventricle** → pumped to lungs via pulmonary artery.
2. Oxygenated blood returns to **left atrium** → flows to **left ventricle** → pumped to the body via aorta.
**Valves (Tricuspid and Mitral):**
Prevent backflow of blood between atria and ventricles, ensuring unidirectional flow.
---
**21. What is Blood pressure? Define systolic and diastolic pressures. Normal values?**
**Answer:**
- **Blood Pressure:** Force exerted by blood on arterial walls.
- **Systolic Pressure:** Pressure during ventricular contraction (~120 mmHg).
- **Diastolic Pressure:** Pressure during ventricular relaxation (~80 mmHg).
- **Normal Range:** 120/80 mmHg.
---
**22. What is lymph? How does it differ from plasma? Functions?**
**Answer:**
- **Lymph:** Extracellular fluid in the lymphatic system; lacks RBCs and platelets.
- **Differences from Plasma:**
- Lymph has fewer proteins.
- Plasma is part of blood; lymph is derived from interstitial fluid.
- **Functions:**
- Lymph transports fats, WBCs, and cellular waste.
- Plasma carries nutrients, hormones, and waste in blood.
**23. Full form of ATP? Why is it called the energy currency? How is it produced? Define endothermic processes.**
**Answer:**
- **ATP:** Adenosine Triphosphate.
- **Energy Currency:** Stores and transfers energy for cellular processes.
- **Production:** Via **cellular respiration** (glycolysis, Krebs cycle, electron transport chain).
- **Endothermic Process:** Requires energy input (e.g., photosynthesis). ATP hydrolysis (ATP → ADP + P) releases energy to drive these processes.
---
**24. Methods of excretion in plants.**
**Answer:**
Plants excrete through:
1. **Stomata** (release O₂ and CO₂).
2. **Lenticels** (release waste gases).
3. **Shedding leaves** (stores waste like tannins).
4. **Storage in vacuoles or as resins/gums.**
---
**25. Location of gastric glands and their secretions.**
**Answer:**
- **Location:** Lining of the stomach.
- **Secretions and Roles:**
- **HCl:** Kills bacteria, activates pepsin.
- **Pepsin:** Digests proteins.
- **Mucus:** Protects stomach lining from acid.
**26. Finger-like projections in the small intestine. Significance and transport of absorbed food.**
**Answer:**
- **Projections:** **Villi** and **microvilli**.
- **Significance:** Increase surface area for nutrient absorption.
- **Transport:** Absorbed nutrients enter blood capillaries (glucose, amino acids) or lacteals (fats). Bloodstream delivers nutrients to cells.
**27. Translocation and plant tissue involved.**
**Answer:**
- **Translocation:** Transport of organic nutrients (e.g., sucrose) from leaves to other parts.
- **Tissue:** **Phloem** (sieve tubes and companion cells).
**28. Biological catalyst in saliva.**
**Answer:**
- **Enzyme:** **Salivary amylase** (breaks starch into maltose).
**29. Differences between blood and lymph.**
**Answer:**
| **Blood** | **Lymph** |
|------------------------------------|------------------------------------|
| Contains RBCs, platelets. | No RBCs or platelets. |
| High protein content. | Low protein content. |
| Flows in blood vessels. | Flows in lymphatic vessels. |
| Red due to hemoglobin. | Colorless. |
| Transports O₂, nutrients. | Transports fats, immune cells. |
Answers to Assertion and Reasoning Questions:
**Question 1**
**Assertion (A):** All organisms consist of some very small living cells.
**Reason (R):** A living cell cannot be dead in any circumstances.
**Answer:**
(c) (A) is true but (R) is false.
**Explanation:**
- **Assertion (A)** is true because the cell theory states that all living organisms are composed of cells.
- **Reason (R)** is false because cells can die (e.g., apoptosis or necrosis). A "living cell" is alive by definition, but cells are not immune to death.
---
**Question 2**
**Assertion (A):** Photosynthesis is a process by which green plants produce glucose-type food in their own body.
**Reason (R):** Oxygen is released in the photosynthesis process.
**Answer:**
(b) Both (A) and (R) are true and (R) is not the correct explanation of (A).
**Explanation:**
- **Assertion (A)** is true: Photosynthesis produces glucose using sunlight, water, and CO₂.
- **Reason (R)** is also true: Oxygen is a byproduct of photosynthesis.
- However, (R) does not explain *how* glucose is produced, so it is not the correct explanation for (A).
---
**Question 3**
**Assertion (A):** Animals have to depend on other animals or plants for food.
**Reason (R):** No animal can produce food in their own body.
**Answer:**
(a) Both (A) and (R) are true and (R) is the correct explanation of (A).
**Explanation:**
- **Assertion (A)** is true: Animals are heterotrophs and rely on external food sources.
- **Reason (R)** is true: Animals lack chloroplasts and cannot perform photosynthesis.
- (R) directly explains why animals depend on others for food, making it the correct explanation.
---
**Question 4**
**Assertion (A):** Energy is produced by combustion of food, initiated by the respiration system.
**Reason (R):** Carbon dioxide is released in the process of respiration.
**Answer:**
(b) Both (A) and (R) are true and (R) is not the correct explanation of (A).
**Explanation:**
- **Assertion (A)** is true: Cellular respiration breaks down food (glucose) to release energy, often compared to "controlled combustion."
- **Reason (R)** is true: CO₂ is a byproduct of respiration.
- However, (R) only states a consequence of respiration and does not explain *how* energy is produced, so it is not the correct explanation.
5) Assertion-Reason Question (Top of the List):
- **Assertion (A):** Aquatic creatures require oxygen more rapidly.
- **Reason (R):** Oxygen in water is less than in the atmosphere.
**Answer: (a) Both (A) and (R) are true, and (R) explains (A).**
*Explanation*: Lower oxygen availability in water drives faster uptake needs.
1. **Which of the following statements about the autotrophs is incorrect?**
**(b) They convert carbon dioxide and water into carbohydrates in the absence of sunlight.**
*Explanation*: Autotrophs perform photosynthesis, which requires sunlight. The absence of sunlight makes this statement false.
2. **A few drops of iodine solution were added to rice water. The solution turned blue-black in colour. This indicates that rice water contains:**
**(b) starch**
*Explanation*: Iodine reacts with starch to produce a blue-black color.
3. **The number of essential nutrient elements in plants:**
**(b) 17**
*Explanation*: Plants require 17 essential elements for growth and metabolism.
4. **The photosynthetic pigment found in Blue-green algae and red algae:**
**(a) Phycology**
*Explanation*: Likely a typo. Blue-green algae (cyanobacteria) use **phycobilins**, and red algae use **phycoerythrin**, but none of the options match. "Phycology" (study of algae) is the closest listed term.
5. **The energy found in photon particles of solar rays:**
**(b) Quantum**
*Explanation*: Energy in photons is quantified as "quanta."
6. **During photosynthesis, oxygen is evolved in:**
**(a) Light reaction**
*Explanation*: Oxygen is produced during the light-dependent reactions of photosynthesis.
7. **Plants that cannot perform photosynthesis:**
**(c) Total stevo parasitic**
*Explanation*: Total parasites (e.g., *Rafflesia*) lack chlorophyll and depend entirely on hosts.
8. **The disc-like structure of granum is called:**
**Thylakoid**
*Explanation*: Thylakoids are stacked in grana.
9. **During light-dependent reaction, light energy is converted into chemical energy (potential energy).**
*Correction*: The statement is correct but contains a typo ("upright" → "light energy").
10. **Light reaction occurs in the presence of sunlight.**
*Explanation*: Light reactions require sunlight to proceed.
11. **Dark reaction is a light-independent reaction.**
*Explanation*: The Calvin cycle (dark reaction) does not directly require light.
12. **ATP combines with phosphate to form ATP.**
*Explanation*: ATP (adenosine triphosphate) already contains phosphates; the question is misleading. Likely intended to state ADP + phosphate → ATP.
13. **Process of energy formation via electron transport:**
**Photophosphorylation**
*Explanation*: Photophosphorylation generates ATP using light energy.
14. **In photosynthesis, chlorophyll is essential.**
*Explanation*: Chlorophyll captures light energy.
15. **Organisms synthesizing organic compounds from CO₂ and water are called:**
**Autotrophs**
*Explanation*: Options "nutriceps/heterotrophs" are incorrect. Likely a typo; the correct term is "autotrophs."
16. **Rafflesia is a partial root parasite.**
*Correction*: Rafflesia is a **total root parasite** (no photosynthesis).
17. **Photosynthesis takes place in organs (e.g., leaves) of carnivorous plants.**
*Explanation*: Carnivorous plants photosynthesize in green tissues.
18. **All plants may not be autotrophs.**
*Explanation*: Parasitic plants (e.g., mistletoe) are heterotrophs.
19. **Fungi are saprophytic organisms.**
*Explanation*: Fungi decompose organic matter.
20. **Carnivorous plants can absorb nitrogen from insects.**
*Explanation*: They trap insects to supplement nitrogen-poor environments.
21. **Orobanche is a total parasite.**
*Explanation*: It lacks chlorophyll and depends entirely on hosts.
22. **Plant-eating animals are called:**
**(b) Herbivorous**
23. **Animals obtaining food from dead bodies:**
**(a) Saprotrophs**
24. **Nutrition from a host:**
**(a) Parasitic nutrition**
**25.** Which of the following is correct?
**(a) Glucose, fructose, galactose – Monosaccharide.**
**26.** Which is not found in plants?
**(b) Galactose**
**27.** Which of the following are disaccharide?
**(b) Sucrose, maltose, lactose**
**28.** Which of the following disaccharide is found in milk?
**(a) Lactose**
**29.** Polysaccharides are–
**(a) Complex and insoluble**
**30.** Which of the following helps in nerve impulse conduction and muscle movement?
**(b) Calcium and Magnesium**
**31.** Which of the following helps in the formation of Chlorophyll?
**(b) Magnesium**
**32.** Which help in the formation of haemoglobin?
**(a) Iron**
**33.** Nutrition in green plants –
**(c) Autotrophs**
**34.** Animal nutrition –
**(b) Heterotrophic nutrition**
**35.** Cholera disease is caused by — in man.
**(b) Bacteria**
**36.** Which nutrients controls metabolic activities?
**(b) Protein**
**37.** Antibody is formed in our body by –
**(a) Protein**
**38.** Which helps in the formation of teeth and bone?
**(a) Calcium**
**39.** Which of the following monosaccharide found in milk?
**(c) Galactose**
**40.** The hormone which is secreted from endocrine part of pancreas –
**(a) Insulin and glucagon**
**41.** Juice of stomach is –
**(a) Acidic**
**42.** Pepsin breaking down paracassinate into–
**(a) Peptone and proteose**
**43.** The partially digested food in stomach is called–
**(a) Chyme**
**44.** Intestinal lipase is
**(b) Lipid splitting enzyme**
**45.** Which of the following cell secrete HCl?
**(d) Parietal cell**
**46.** Which of the following juice not contain enzyme?
**(a) Bile juice**
**47. Which enzyme is found in pancreatic juice?**
**Answer:** (a) Amylopsin
**Explanation:** Pancreatic juice contains enzymes like amylase (amylopsin), lipase, and proteases. Pepsin is produced in the stomach, and erepsin is found in intestinal juice.
**48. The rate of respiration in plants compared to animals.**
**Answer:** Very slow
**Explanation:** Plants have a slower metabolic rate and thus respire at a much slower pace compared to animals.
**49. Tree absorbs \( O_2 \) during respiration through:**
**Answer:** Lenticel
**Explanation:** Lenticels are small openings on stems and roots that allow gas exchange, especially when stomata are closed.
**50. Organic compound storing energy from cellular respiration.**
**Answer:** ATP
**Explanation:** ATP (adenosine triphosphate) is the primary energy carrier produced during cellular respiration.
**51. Cellular respiration occurs in:**
**Answer:** Mitochondria
**Explanation:** The mitochondria are the powerhouse of the cell, where most ATP is generated via aerobic respiration.
**52. Plant respiration occurs:**
**Answer:** Both day and night
**Explanation:** Respiration is a continuous process in plants, occurring 24/7.
**53. System supplying nutrients and oxygen to cells:**
**Answer:** (b) Circulatory system
**Explanation:** The circulatory system transports oxygen and nutrients to cells via blood.
**54. Granular white blood corpuscle:**
**Answer:** Neutrophil
**Explanation:** Neutrophils, eosinophils, and basophils are granular WBCs. Among the options, neutrophil is granular.
**55. Cavity between heart membranes:**
**Answer:** Pericardial cavity
**Explanation:** The pericardial cavity surrounds the heart and contains lubricating fluid.
**56. Aperture between auricle and ventricle:**
**Answer:** Ventriculi auricular aperture
**Explanation:** The atrioventricular aperture connects the atrium (auricle) and ventricle.
**57. Valve with two cartilaginous flaps:**
**Answer:** Bicuspid valve
**Explanation:** The bicuspid (mitral) valve has two flaps and is located between the left atrium and ventricle.
**58. Human heart chambers:**
**Answer:** 4
**Explanation:** The heart has two atria (auricles) and two ventricles.
**59. Blood-to-plasma ratio:**
**Answer:** 55%–45%
**Explanation:** Blood plasma constitutes ~55%, and cells make up ~45%.
**60. Systemic aorta opens at:**
**Answer:** Left ventricle
**Explanation:** The aorta originates from the left ventricle to supply oxygenated blood to the body.
**61. Systemic aorta carries blood from:**
**Answer:** (d) Left ventricle
**Explanation:** The left ventricle pumps blood into the systemic aorta.
**62. Chamber with deoxygenated blood:**
**Answer:** (d) Both (a) and (b)
**Explanation:** Deoxygenated blood is present in the right atrium and right ventricle.
**63. Mitral valve location:**
**Answer:** (d) Between left auricle and ventricle
**Explanation:** The mitral (bicuspid) valve is between the left atrium and ventricle.
**64. WBC involved in antibody formation:**
**Answer:** (b) Lymphocyte
**Explanation:** B-lymphocytes produce antibodies.
**65. Granular WBC:**
**Answer:** (a) Neutrophil, (c) Eosinophil, (d) Basophil
**Explanation:** Neutrophils, eosinophils, and basophils are granular. However, if only one option is allowed, (a) Neutrophil is the most common answer.
**66. Correct statement about heterotrophs:**
**Answer:** (b) Heterotrophs don’t synthesize their own food.
**Explanation:** Heterotrophs rely on external food sources.
**67. Sequence of alimentary canal:**
**Answer:** (c) Mouth → oesophagus → stomach → small intestine → large intestine
**Explanation:** Correct anatomical order.
**68. Part receiving bile from the liver:**
**Answer:** (c) Small intestine
**Explanation:** Bile is stored in the gallbladder and released into the duodenum (small intestine).
**69. Stomach lining protection from HCl:**
**Answer:** (c) Mucus
**Explanation:** Mucus secreted by gastric glands protects the stomach lining.
**70. Lime water turns milky due to:**
**Answer:** (a) Carbon dioxide
**Explanation:** CO₂ reacts with lime water to form insoluble calcium carbonate, causing cloudiness.
**71. The correct sequence of anaerobic respiration in yeast is-**
**(b) Glucose cytoplasm → pyruvate cytoplasm → Ethanol + carbon dioxide.**
*Explanation:* Yeast undergoes alcoholic fermentation in the cytoplasm. Pyruvate (from glycolysis in the cytoplasm) is converted into ethanol and CO₂, not lactic acid or in mitochondria.
**72. During respiration, exchange of gases takes place in-**
**(a) alveoli of lungs**
*Explanation:* Gas exchange occurs in the alveoli, where oxygen diffuses into the blood and CO₂ diffuses out. The trachea and larynx are airways, not exchange sites.
**73. What prevents the backflow of blood from ventricles to auricles during ventricular contraction?**
**(a) both tricuspid and bicuspid valves**
*Explanation:* The tricuspid (right side) and bicuspid/mitral (left side) valves close to prevent backflow into the atria when ventricles contract.
**74. In which vertebrate group(s) does the heart not pump oxygenated blood to the body?**
**(c) Pisces only**
*Explanation:* Fish have a two-chambered heart that pumps deoxygenated blood to the gills. Oxygenated blood then flows directly to tissues without being pumped again. Amphibians pump oxygenated blood despite having a three-chambered heart.
**75. The opening and closing of stomatal pores depend upon-**
**(c) water in guard cells**
*Explanation:* Guard cells become turgid (open stomata) or flaccid (close stomata) based on water content.
**76. Lack of oxygen in muscles leads to cramps. This is due to-**
**(c) Conversion of pyruvate to lactic acid**
*Explanation:* Anaerobic respiration in muscles produces lactic acid, causing fatigue and cramps.
**77. The blood leaving the tissues becomes richer in-**
**(b) carbon dioxide**
*Explanation:* Tissues release CO₂ as a waste product, which diffuses into the blood.
**78. We test for starch and not glucose to prove photosynthesis because-**
**(a) Glucose formed during photosynthesis gets converted to starch**
*Explanation:* Glucose is rapidly converted to starch for storage, making starch a better indicator for testing photosynthesis.
**79. Stomata play an important role in-**
**(d) all the above (photosynthesis, transpiration, respiration)**
*Explanation:* Stomata facilitate gas exchange for photosynthesis/respiration and water loss (transpiration).
**80. Correct labeling of the stomata diagram:**
**(a) 1. Epidermal cells, 2. Stoma, 3. Guard cell, 4. Chloroplast**
*Explanation:* Guard cells (3) surround the stoma (2), contain chloroplasts (4), and are flanked by epidermal cells (1).
**81. For the experiment, keeping the plant in darkness first is to-**
**(a) destarch the leaves**
*Explanation:* Darkness depletes existing starch, ensuring any starch detected later is from photosynthesis during the experiment. (Note: The provided option "deactive the chloroplasts" is incorrect, but this is the intended answer based on the question's phrasing.)
**For the setup showing CO₂ release during respiration:**
**(b) II** (assuming Setup II uses germinating seeds in a flask with lime water turning cloudy, indicating CO₂).
Here is the complete list of **questions (82–89)** paired with their **answers** based on the provided content:
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**Question 82**
**Task:** Write one common feature for each pair:
(a) **Gills and lungs**
**Answer:** Both are respiratory organs involved in gas exchange.
(b) **Arteries and veins**
**Answer:** Both have three structural layers (tunica externa, media, and intima).
(c) **Chlorophyll and haemoglobin**
**Answer:** Both contain metal ions (Mg in chlorophyll, Fe in haemoglobin).
(d) **Glycogen and starch**
**Answer:** Both are storage polysaccharides.
---
**Question 83**
**Task:** Where does the breakdown of pyruvate into CO₂, water, and energy occur?
**Options:** (a) Chloroplast, (b) Nucleus, (c) Cytoplasm, (d) Mitochondria
**Answer:** (d) Mitochondria (via the Krebs cycle).
---
**Question 84**
**Task:** Which figure(s) do NOT illustrate steps of the experiment proving "light is necessary for photosynthesis"?
**Options:** (a) I and III, (b) II, (c) I and II, (d) I, II, and IV
**Answer:** (d) I, II, and IV (they likely omit steps like destarching, light exposure, or starch testing).
---
*Question 85**
**Task:** Correctly label parts I–IV in a stomatal apparatus sketch.
**Options:**
(a) I: Guard cell, II: Stoma, III: Starch granule, IV: Nucleus
(b) I: Cytoplasm, II: Nucleus, III: Stoma, IV: Chloroplast
(c) I: Guard cell, II: Starch, III: Nucleus, IV: Stoma
(d) I: Cytoplasm, II: Chloroplast, III: Stoma, IV: Nucleus
**Answer:** (a) I: Guard cell, II: Stoma, III: Starch granule, IV: Nucleus
---
**Question 86**
**Task:** Which chemicals are used for staining and mounting a leaf peel to observe stomata?
**Options:** (a) Safranin and glycerine, (b) Glycerine and iodine, (c) Safranin and iodine, (d) Iodine and safranin
**Answer:** (a) Safranin (stains cells) and glycerine (preserves the mount).
---
*Question 87**
**Task:** In a stained leaf peel, which cells show nuclei under a microscope?
**Options:**
(a) Guard cells and epidermal cells
(b) Guard cells only
(c) Guard cells, epidermal cells, and stomata
(d) Epidermal cells only
**Answer:** (a) Guard cells and epidermal cells (both have visible nuclei).
---
**Question 88**
**Task:** Why does the water level rise in the bent tube during the experiment showing "CO₂ is released during respiration"?
**Options:**
(a) Seeds consume O₂ and release CO₂, which is absorbed by KOH, reducing gas pressure.
(b) Seeds consume all O₂ and CO₂.
(c) Seeds need water for growth.
(d) CO₂ is released.
**Answer:** (a) Germinating seeds consume O₂ and release CO₂; KOH absorbs CO₂, lowering pressure and causing water to rise.
---
**Question 89**
**Task:** Why is a water bath used to boil a leaf in alcohol during the "light is essential for photosynthesis" experiment?
**Options:**
(a) Alcohol is flammable
(b) Water boils at a lower temperature
(c) Steam heats the leaf faster
(d) Steam dissolves chlorophyll
**Answer:** (a) Alcohol is flammable; the water bath prevents direct heating and fire hazards.
**Answers:**
**Question:(90)** A student covered the dorsal surface of a leaf with black paper. After testing for starch, the result was:
**Answer:** (c) the dorsal surface of the leaf was white but the ventral surface turned blue-black.
**Question (91):** Lack of salivary amylase affects:
**Answer:** (d) starch breaking down into sugars.
**Question (92):** Contraction/expansion of food pipe walls is called:
**Answer:** (b) peristaltic movement.
**Question (93):** Movement of food in phloem:
**Answer:** (b) translocation.
**Question (94):** Blood cleaning by separating urea:
**Answer:** (c) dialysis.
**Question (95):** After energy use, ATP is:
**Answer:** ATP is converted to ADP.
**Question (96):** Incomplete glucose oxidation produces:
**Answer:** will be produced.
**Question (97):** Glycolysis forms:
**Answer:** pyruvic acid.
**Question (98):** Enzyme aiding fermentation:
**Answer:** zymase.
**Question (99):** Tadpole respiration:
**Answer:** gills.
**Question (100):** Cellular substance movement:
**Answer:** (a) Cyclosis.
**Question (101):** Tissues for plant circulation:
**Answer:** (c) Both xylem and phloem.
**Question (102):** Dry seed swelling in water:
**Answer:** (b) Imbibition.
**Question (103):** Central kidney part:
**Answer:** (b) medulla.
**Question (104):** Nephron blood filtration site:
**Answer:** (a) Glomerulus.
**Question (105):** Daily water filtration by adult:
**Answer:** (a) 180 liters.
**Question (106):** Hemoglobin breakdown into bilirubin:
**Answer:** (c) Liver.
**Question (107):** Urine elimination path:
**Answer:** (a) kidney → ureters → urinary bladder → urethra.
**Fill-in-the-Blank :**
1. **(i)**
**Question:** ______ system is absent in plant body.
**Answer:** **Nervous**
2. **(ii)**
**Question:** All the components of food are not found in simple and ______ form.
**Answer:** **complex**
3. **(iii)**
**Question:** The process of absorption of simple molecules formed during digestion and their transformation into cellular material is called ______.
**Answer:** **assimilation**
4. **(iv)**
**Question:** Those organisms which feed both plants and animals are called ______.
**Answer:** **omnivores**
5. **(v)**
**Question:** ______ parasite causes malaria fever.
**Answer:** **Plasmodium**
6. **(vi)**
**Question:** ______ endoparasite causes amoebic dysentery.
**Answer:** **Entamoeba histolytica**
7. **(vii)**
**Question:** The process of production of energy during cellular oxidation is called ______.
**Answer:** **cellular respiration**
8. **(viii)**
**Question:** Cellulose is ______, which is found in plants.
**Answer:** **a polysaccharide**
9. **(ix)**
**Question:** Protein forms ______ solution in water.
**Answer:** **colloidal**
10. **(x)**
**Question:** Protein is polymer of ______.
**Answer:** **amino acids**
11. **(xi)**
**Question:** ______ protein is found in the hair, nail, horn, and hoof of animals.
**Answer:** **Keratin**
12. **(xii)**
**Question:** ______ protein helps in the formation of antibody in our body.
**Answer:** **Immunoglobulin**
13. **(xiii)**
**Question:** ______ element is found in chlorophyll.
**Answer:** **Magnesium**
14. **(xiv)**
**Question:** ______ element is found in haemoglobin.
**Answer:** **Iron**
15. **(xv)**
**Question:** The organism which can produce their own food and fulfill their nutritional requirement is called ______ nutrition.
**Answer:** **autotrophic**
16. **(xvi)**
**Question:** The organism which cannot produce their own food and obtain nutrition from others is called ______ nutrition.
**Answer:** **heterotrophic**
17. **(xvii)**
**Question:** Those organisms which obtain nutrients from dead or decaying substances are called ______.
**Answer:** **saprophytes**
18. **(xviii)**
**Question:** ______ is the chief body-building substance.
**Answer:** **Protein**
19. **(xix)**
**Question:** Glucose, fructose, maltose, and starch are togetherly known as ______.
**Answer:** **carbohydrates**
20. **(xx)**
**Question:** In cellular respiration, energy will be produced from monosaccharide ______.
**Answer:** **glucose**
21. **(xxi)**
**Question:** ______ is a plant polysaccharide, and ______ is an animal polysaccharide.
**Answer:** **Cellulose** (plant), **glycogen** (animal)
22. **(xxii)**
**Question:** ______ protein helps in the coagulation of blood.
**Answer:** **Fibrin**
23. **(xxiii)**
**Question:** ______ lipid is found in the human body.
**Answer:** **Triglyceride**
24. **(xxiv)**
**Question:** The lipid found in liquid state at room temperature is known as ______.
**Answer:** **oil**
25. **(xxv)**
**Question:** The secretion of the salivary gland is called ______.
**Answer:** **saliva**
26. **(xxvi)**
**Question:** ______ hormone is secreted from the endocrine part of the pancreas.
**Answer:** **Insulin**
27. **(xxvii)**
**Question:** There is no ______ in bile juice.
**Answer:** **enzyme**
28. **(xxviii)**
**Question:** Bile salt produces ______ from fats.
**Answer:** **emulsification**
29. **(xxix)**
**Question:** ______ and ______ will be produced as a result of digestion of lipid.
**Answer:** **Fatty acids**, **glycerol**
30. **(xxx)**
**Question:** ______ will be produced as a result of carbohydrate digestion.
**Answer:** **Glucose**
31. **(xxxi)**
**Question:** ______ will be formed as a result of protein digestion.
**Answer:** **Amino acids**
32. **(xxxii)**
**Question:** The exit of food from the stomach is regulated by a ______ muscle.
**Answer:** **pyloric sphincter**
33. **(xxxiii)**
**Question:** ______ is the longest part of the alimentary canal.
**Answer:** **Small intestine**
34. **(xxxiv)**
**Question:** The inner lining of the small intestine has numerous finger-like projections called ______.
**Answer:** **villi**
35. **(xxxv)**
**Question:** In fish, blood goes ______ through the heart, whereas in humans, blood goes ______ through the heart.
**Answer:** **once** (fish), **twice** (humans)
36. **(xxxvi)**
**Question:** The transport of soluble products of photosynthesis is called ______.
**Answer:** **translocation**
37. **(xxxvii)**
**Question:** ______ is mostly essential for the living organisms of the world.
**Answer:** **Water**
38. **(xxxviii)**
**Question:** ______ is the prime source of energy.
**Answer:** **Sunlight**
39. **(xxxix)**
**Question:** ______ pigment can help trap sunlight during photosynthesis.
**Answer:** **Chlorophyll**
40. **(XL)**
**Question:** Chloroplast is absent in ______ algae and bacteria.
**Answer:** **blue-green**
41. **(XLI)**
**Question:** ______ is considered the reaction centre of photosystem I.
**Answer:** **P700**
42. **(XLII)**
**Question:** In light reaction, solar energy is converted into ______ energy.
**Answer:** **chemical**
43. **(XLIII)**
**Question:** ______ is known as the functional unit of photosynthesis.
**Answer:** **Chloroplast**
44. **(XLIV)**
**Question:** Appearance of ______ disease in plants due to lack of mineral salts.
**Answer:** **chlorosis**
----------------Next Page-------------------
1. **(XLV)** Light reaction occurs in ______ part of chlorophyll.
**Answer:** thylakoid
2. **(XLVI)** During photosynthesis the photon particles of solar ray, of ______ wave length can be used by plants.
**Answer:** visible (400-700 nm)
3. **(XLVII)** The photosynthetic process is a complex chemical reaction of ______ and ______.
**Answer:** carbon dioxide and water
4. **(XLVIII)** In light reaction of photosynthesis production of \( O_2 \), ATP and ______.
**Answer:** NADPH
5. **(XLIX)** The group of photosynthetic pigment in reaction centre is called ______.
**Answer:** reaction center chlorophyll (or photosystem)
6. **(L)** ______ is the factors of starch synthesis.
**Answer:** ATP and NADPH
7. **(LI)** In Calvin cycle, the organic compound — absorb \( CO_2 \).
**Answer:** RuBP (Ribulose-1,5-bisphosphate)
8. **(LII)** The insectivorous plants can absorb — from insects.
**Answer:** nitrogen/nutrients
9. **(LIII)** ______ plants are harmful to host plants.
**Answer:** Parasitic
10. **(LIV)** ______ is a partial stem parasite.
**Answer:** Mistletoe
11. **(LV)** Those plants which can absorb food from the stem of host plants, such plants are called ______.
**Answer:** stem parasites (or haustorial parasites)
12. **(LVI)** ______ is a total root parasite which is found in tomato.
**Answer:** Orobanche
13. **(LVII)** ______ helps in absorption of food from the stem of host plant.
**Answer:** haustoria
14. **(LVIII)** ______ is the food sucking organ of parasitic plant.
**Answer:** haustorium
15. **(LIX)** In nepenthes, pitcher is a modification of ______.
**Answer:** leaf
16. **(LX)** The bag-like structure of *Utricularia* is a modification of ______.
**Answer:** leaf
17. **(LXI)** *Drosera* possess ______ to trap the insects.
**Answer:** sticky tentacles
18. **(LXII)** *Monotropa* is a ______ flowering plant.
**Answer:** saprophytic (or non-photosynthetic)
19. **(LXIII)** ______ plants can obtain their nourishment from dead or decaying substances.
**Answer:** Saprophytic
20. **(LXIV)** During the respiratory process \( CO_2 \), water molecule and ______ will be formed.
**Answer:** ATP
21. **(LXV)** Respiration is a ______ process.
**Answer:** catabolic
22. **(LXVI)** During anaerobic respiration, in muscle cell ______ will be formed.
**Answer:** lactic acid
23. **(LXVII)** The Krebs' cycle occurs in ______ of the cell.
**Answer:** mitochondrial matrix
24. **(LXVIII)** ______ is a physical process which occurs outside the cell.
**Answer:** Diffusion
25. **(LXIX)** In aquatic condition frog can respire through ______.
**Answer:** skin (cutaneous respiration)
26. **(LXX)** The exchange of \( O_2 \) and \( CO_2 \) in between alveoli and blood capillaries through ______ membrane.
**Answer:** alveolar-capillary
27. **(LXXI)** Oxygen and haemoglobin combine to form an unstable compound ______.
**Answer:** oxyhemoglobin (HbO₂)
28. **(LXXII)** Glycolysis occurs in ______ of a cell.
**Answer:** cytoplasm (cytosol)
29. **(LXXIII)** \( Hb_4 + 4O_2 \) ______.
**Answer:** → Hb₄O₈ (oxyhemoglobin)
30. **(LXXIV)** The life process, through which oxidation of food molecule to yield energy is known as ______.
**Answer:** respiration
31. **(LXXV)** The main product of cellular respiration is ______.
**Answer:** ATP
32. **(LXXVI)** The high energy bond of ATP is called ______.
**Answer:** phosphoanhydride bond
33. **(LXXVII)** The fermentation occurs in yeast is known as ______.
**Answer:** alcoholic fermentation
34. **(LXXVIII)** The fermentation occurs in muscle cell is known as ______.
**Answer:** lactic acid fermentation
35. **(LXIX)** The exchange of respiratory gases is called ______.
**Answer:** gas exchange
36. **(LXXX)** The exchange of gases occurs through ______ in amoeba and other unicellular animals.
**Answer:** cell membrane (simple diffusion)
37. **(LXXXI)** ______ is essential to oxidize organic food.
**Answer:** Oxygen
38. **(LXXXII)** Plant roots absorb oxygen which are present in soil pores for ______ and the oxygen is absorbed by ______.
**Answer:** respiration; root hairs
39. **(LXXXIII)** In night, plants remove ______ by different process and absorb ______.
**Answer:** CO₂; O₂
40. **(LXXXIV)** ______ and ______ are major excretory substances produced in plants during respiratory process.
**Answer:** CO₂ and H₂O
41. **(LXXXV)** ______ is a type of excretory process.
**Answer:** Guttation
42. **(LXXXVI)** 90% water of plant body can be released by ______ transpiration.
**Answer:** stomatal
43. **(LXXXVII)** ______ is found in the epidermis of plant leaf.
**Answer:** stomata
44. **(LXXXVIII)** In plant the water is absorbed by roots and passed through xylem and ultimately the water is found in ______ cell.
**Answer:** mesophyll
45. **(LXXXIX)** If temperature increases then transpiration will be ______.
**Answer:** increased
46. **(XC)** If the water vapour is more in air then the rate of transpiration will be ______.
**Answer:** decreased
47. **(XCI)** If the guard cells are filled up with fluids then the stomata will be ______.
**Answer:** open
-------------------------- Next Page -----------------------------+
**(XCII) The plant body becomes _turgid_ due to transpiration.**
Transpiration creates a suction force (transpiration pull) that maintains turgidity in plant cells by drawing water upward from the roots.
**(XCIII) In plants _transpiration_ is harmful however it is mostly essential.**
While transpiration is essential for nutrient transport and cooling, excessive water loss can lead to dehydration and stress.
**(XCIV) The transpiration occurs through stomata is called _stomatal_ transpiration.**
Stomata are the primary pores through which most transpiration occurs.
**(XCV) When a dry gram seed is immersed in water, it swells. Such phenomenon is called _imbibition_.**
Imbibition is the absorption of water by hydrophilic substances (e.g., seed coat), causing swelling.
**(XCVI) Imbibition is a _physical_ process.**
It involves adsorption of water without chemical reactions, making it a physical process.
**(XCVII) The cyclosis of cellular substance is an _active_ process.**
Cytoplasmic streaming (cyclosis) requires ATP and is thus energy-dependent.
**(XCVIII) When diffusion of solvent occurs from a lower concentrated solution to a higher concentrated solution through a semi-permeable membrane, such process is called _osmosis_.**
Osmosis is the movement of solvent (water) across a membrane from low solute concentration to high solute concentration.
**(XCIX) _Cellulose_ is a characteristic of plant cell wall.**
Plant cell walls are primarily composed of cellulose, providing structural rigidity.
**(C) The process of movement of molecules from higher concentration to lower concentration is called _diffusion_.**
Diffusion is the passive movement of molecules down their concentration gradient.
**(CI) The water enters into the root from the soil by the process _osmosis_.**
Water moves via osmosis from soil (higher water potential) into root cells (lower water potential).
**(CII) Xylem consists of _tracheids_ and _vessels_.**
These are the two main water-conducting elements in xylem tissue.
**(CIII) The essential salts of plants are found in the soil as _ionic_ electrically charged _particles_.**
Minerals in soil exist as dissolved ions (e.g., K⁺, NO₃⁻), which plants absorb.
**(CIV) Carbohydrate is synthesized in _chloroplasts_ of plants.**
Photosynthesis occurs in chloroplasts, producing glucose and other carbohydrates.
**(CV) The xylem and phloem together are known as _vascular bundles_.**
They form the plant’s vascular system for transport.
**(CVI) In plants, the conduction of water and mineral salts is called _ascent of sap_.**
This term specifically refers to the upward movement of water and minerals through xylem.
**(CVII) The process of conduction of food in plants is called _translocation_.**
Translocation occurs via phloem, transporting sugars and nutrients.
**(CVIII) _Urea_ is formed as a result of metabolism of amino acid in the liver.**
The urea cycle converts excess amino acids into urea for excretion.
**(CIX) Uric acid is formed as a result of metabolism of _purine_ acid.**
Uric acid is a byproduct of purine nucleotide breakdown.
**(CX) _Urea_ acid is formed from ammonia.**
Ammonia is detoxified in the liver by conversion to urea (note: urea is technically not an acid, but this is likely the intended answer).
**(CXI) The excretory organ of man and other vertebrate animals is _kidney_.**
Kidneys filter blood, remove waste, and produce urine.
**(CXII) The Malpighian corpuscles are formed by Bowman's capsule and _glomerulus_.**
Together, they form the functional unit for blood filtration in the kidney.
**Answers:**
**(CXIII) The 'U' shaped renal tubule is called _loop of Henle_.**
The loop of Henle is a U-shaped structure in the nephron responsible for creating a concentration gradient in the kidney medulla.
**(CXIV) The gaseous excretory substance of animals is _carbon dioxide_.**
Carbon dioxide (\(CO_2\)) is a waste product of cellular respiration and is excreted via the lungs.
**(CXV) The structural and functional unit of human kidney is _nephron_.**
Each nephron consists of a renal corpuscle (Bowman's capsule and glomerulus) and renal tubule, performing filtration, reabsorption, and secretion.
**(CXVI) The process of removal of unwanted excretory substances is known as _excretion_.**
Excretion refers to the elimination of metabolic wastes (e.g., urea, \(CO_2\)) from the body.
**(CXVII) In liver, ammonia is converted to _urea_.**
The urea cycle in the liver detoxifies ammonia by converting it into urea, which is excreted in urine.
**(CXVIII) The concave part of kidney is known as _hilum_.**
The hilum is the indented region where blood vessels, nerves, and the ureter connect to the kidney.
**(CXIX) The bunch of capillaries inside the Bowman's capsule is known as _glomerulus_.**
The glomerulus filters blood under high pressure, allowing small molecules to pass into Bowman's capsule.
**(CXX) All the collecting tubes of kidney unite to form _collecting duct_ tubule of nephron.**
Collecting ducts receive filtrate from multiple nephrons and transport it to the renal pelvis.
**(CXXI) The _proximal convoluted tubule_ tubule of nephron secretes creatine, creatinine to the nephric filtrate.**
The proximal convoluted tubule actively secretes waste products like creatinine into the filtrate.
**(CXXII) _Sweat_ and _sebaceous_ glands are found in the skin of mammals.**
Sweat glands regulate temperature and excrete salts, while sebaceous glands secrete oils to lubricate the skin.
**(CXXIII) _Collecting duct_ tubule collects urine.**
The collecting duct consolidates urine and transports it to the renal pelvis for excretion.
3. Determine True/False:
**(i)** Autotrophic nutrition does not involve any source of energy to synthesize food from simple inorganic materials available in the environment.
**Answer:** False
**(ii)** In human beings, the chief excretory substance is glucose.
**Answer:** False
**(iii)** Each kidney has a large number of filtration units called Bowman’s capsules.
**Answer:** False
**(iv)** When there is a lack of oxygen in our muscle cells, pyruvate is converted into amino acid.
**Answer:** False
**(v)** The small intestine of herbivores is longer than that of the carnivores.
**Answer:** True
**(vi)** Bile juice from the liver is acidic in nature.
**Answer:** False
**(vii)** Enzyme trypsin converts fats into glycerols.
**Answer:** False
**(viii)** The main principle of plant and animal respiration are the same.
**Answer:** True
**(ix)** In plant respiration, the exchange of oxygen takes place between plants and the atmosphere.
**Answer:** True
**(x)** In plants, the presence of a respiratory system is required for respiration.
**Answer:** False
(xi) Plant respiration continues although absence of organic food.
**True** (Plants respire stored carbohydrates).
(xii) Movement of water from soil to the root of the plant through osmosis diffusion.
**True** (Osmosis drives water uptake).
(xiii) The elements are found in soil in the form of salt/ion.
**True** (Minerals are absorbed as ions).
(xiv) The plant root absorbs water along with mineral ion. These are passed through xylem in upward/downward movement.
**True** (Xylem transports water/minerals upward).
(xv) The plant-produced food is circulated in the form of solid state/insoluble state.
**False** (Phloem transports soluble sugars).
(xvi) In plants, food is produced in leaves, from this the food is passed in upward/downward/lateral direction.
**True** (Phloem transports bidirectionally).
(xvii) The plant-produced food is circulated to different parts of the plant body through phloem.
**True** (Phloem transports food).
(xviii) Root hairs absorb water due to root pressure.
**True** (Root pressure aids absorption).
(xix) Cells in plant leaves with more chlorophyll are called palisade cells.
**True** (Palisade mesophyll is chlorophyll-rich).
(xx) The photosynthetic pigment in bacteria is bacteriochlorophyll.
**True**.
(xxi) Photosynthesis requires solar energy, chlorophyll, CO₂, and H₂O.
**True**.
(xxii) Dark reaction does not take place in day time.
**False** (Occurs simultaneously with light reactions).
(xxiii) Conversion of PGA to PGAL uses ATP and NADPH from light reactions.
**True**.
(xxv) Lactic acid accumulation causes muscle fatigue.
**True**.
(xxv) Krebs cycle occurs before glycolysis.
**False** (Glycolysis precedes Krebs).
(xxvi) Insect respiratory organ is trachea.
**True**.
(xxvii) Mammals respire through skin.
**False** (Primarily lungs; exceptions like amphibians).
(xxviii) Alveoli and capillary membranes form the respiratory membrane.
**True**.
(xxix) Plant transpiration occurs through roots.
**False** (Occurs via stomata).
(xxx) Guard cells have no role in stomatal transpiration.
**False** (Guard cells regulate stomata).
(xxxix) Transpiration releases water in liquid form.
**False** (Vapor form; guttation is liquid).
(xxxix) Excessive transpiration inhibits plant growth.
**True**.
(xxxix) Transpiration controls plant temperature.
**True**.
(xxxix) Transpiration sometimes inhibits gas exchange.
**True** (Stomatal closure affects gas exchange).
(xxxx) Transpiration aids upward water movement.
**True** (Cohesion-tension theory).
(xxxxvi) Transpiration regulates cytoplasm concentration.
**True** (Water loss affects cell water content).
(xxxxvii) Turgid guard cells open stomata.
**True**.
(xxxxviii) Imbibition, diffusion, osmosis are biological processes.
**False** (Physical processes).
(xxxix) Solids absorb liquids due to surface tension.
**False** (Imbibition is due to affinity).
(xl) Diffusion moves molecules from lower to higher concentration.
**False** (High to low concentration).
(xli) Cell solvent (water) moves via diffusion.
**False** (Osmosis governs water movement).
(xlii) Diffusion is a biological process.
**False** (Physical process).
(xliii) Plasma membrane is semipermeable.
**True**.
(xliv) Dry seed swelling in water is due to diffusion.
**False** (Imbibition).
(xlv) Right auricle contains oxygenated blood.
**False** (Deoxygenated blood).
(xlvi) Right auricle is larger than left auricle.
**False** (Similar in size).
(xlvii) Right ventricle wall is larger than left auricle.
**True** (Ventricle walls are thicker than atria).
(xlviii) Superior vena cava opens into the right auricle.
**True**.
(xlix) Systemic aorta carries deoxygenated blood.
**False** (Carries oxygenated blood).
(l) Tricuspid valve lies at the aortic opening.
**False** (Aortic valve is present).
(li) Valve between right auricle and ventricle is tricuspid.
**True**.
(lii) Tricuspid valve has three cartilaginous flaps.
**True** (Three cusps).
**Answers:**
**(liii)** The red blood cells of human blood are round in shape.
**False** (They are biconcave discs, not simply "round").
**(liv)** All artery carries oxygenated blood.
**False** (The pulmonary artery carries deoxygenated blood).
**(iv)** All veins of our body carries deoxygenated blood.
**False** (The pulmonary veins carry oxygenated blood).
**(1vi)** The pulmonary veins carries deoxygenated blood.
**False** (Pulmonary veins carry oxygenated blood).
**(1vii)** The pulmonary aorta carries oxygenated blood.
**False** (The term "pulmonary aorta" is incorrect; the pulmonary artery carries deoxygenated blood).
**(1viii)** The red blood cells of human blood are nucleated.
**False** (Mature human RBCs lack nuclei).
**(1ix)** Mammalian red blood cells are nucleated.
**False** (Most mammalian RBCs, including humans, are enucleated).
**(1x)** The pericardial fluid is present in the pericardial cavity of heart.
**True** (It reduces friction during heartbeats).
**(ii)** The red blood cells contain haemoglobin.
**True** (Hemoglobin is the oxygen-carrying protein in RBCs).
**(1ii)** The pulmonary aorta carries deoxygenated blood.
**False** (The term "pulmonary aorta" is incorrect; the pulmonary artery carries deoxygenated blood).
Answer these questions:
**4. What do you mean by life processes?**
Life processes are the fundamental biological activities essential for maintaining life in organisms. These include **nutrition, respiration, excretion, transportation, growth, reproduction, and response to stimuli**. They ensure survival and proper functioning of the organism.
**5. What is called nutrition?**
Nutrition is the process by which organisms obtain and utilize food for energy, growth, repair, and maintenance. It involves **ingestion, digestion, absorption, assimilation, and egestion**.
**6. What is called respiration?**
Respiration is the biochemical process where cells break down glucose (in the presence of oxygen) to release energy (ATP), carbon dioxide, and water. It occurs in mitochondria and is vital for cellular functions.
**7. Name one chemical substance which coordinates biological functions in the human body.**
**Hormones**, such as **insulin**, act as chemical messengers. Insulin regulates blood sugar levels by facilitating glucose uptake into cells.
**8. What is called digestion?**
Digestion is the breakdown of complex food molecules into simpler, absorbable substances through **mechanical (chewing) and chemical (enzymatic) processes**.
**9. What do you mean by food? Give example.**
Food is any nutrient-rich substance consumed to provide energy and materials for growth and repair. Example: **Rice, vegetables, eggs, or meat**.
**10. What are different types of organisms based on their food procurement?**
- **Autotrophs**: Produce their own food (e.g., plants via photosynthesis).
- **Heterotrophs**: Depend on others for food:
- **Herbivores** (plant-eaters),
- **Carnivores** (meat-eaters),
- **Omnivores** (both plants and meat),
- **Parasites** (live on a host),
- **Saprophytes** (feed on dead matter).
**11. What is called photosynthesis?**
Photosynthesis is the process by which green plants, algae, and some bacteria convert **light energy, CO₂, and H₂O** into glucose and oxygen using chlorophyll.
**12. Write down the chemical reaction which occurs in photosynthesis.**
(See the chemical reaction from book)
**13. What is called producer? Give example.**
Producers (autotrophs) synthesize their own food. Example: **Plants, algae, or cyanobacteria**.
**14. What is called holozoic organism? Give example.**
Holozoic organisms ingest solid food, digest it internally, and absorb nutrients. Example: **Humans, lions, or amoeba**.
**15. What is called parasite? Give one example of ectoparasite.**
A parasite lives on or in a host, deriving nutrients at the host’s expense. Example of ectoparasite: **Lice or ticks**.
**16. What is called host? Give example.**
A host is an organism that harbors a parasite. Example: **A human infected with tapeworm**.
**17. Write down the name of two endoparasites.**
- **Tapeworm** (resides in intestines),
- **Plasmodium** (causes malaria, lives in red blood cells).
**18. What is called cellular respiration?**
Cellular respiration is the metabolic process in mitochondria where glucose is oxidized to produce ATP, CO₂, and H₂O. It can be **aerobic** (with oxygen) or **anaerobic** (without oxygen).
**19. Name two proteins which help in blood clotting.**
- **Fibrinogen** (converted to fibrin to form clots),
- **Thrombin** (enzyme that activates fibrinogen).
**20. Name the pigments of human blood which help in conduction of oxygen.**
- **Hemoglobin** (in red blood cells, binds oxygen),
- **Myoglobin** (in muscles, stores oxygen).
**21. In which component of food is maximum energy found?**
**Fats (lipids)** provide the highest energy per gram (9 kcal/g), compared to carbohydrates (4 kcal/g) and proteins (4 kcal/g).
**22. Name the bacteria-destroying enzyme of saliva.**
**Lysozyme** breaks down bacterial cell walls, preventing infections in the mouth.
**23. Name the enzyme which is found in Saliva.**
**Answer:** Salivary amylase (also called ptyalin). It breaks down starch into maltose.
**24. What is called the digestive system?**
**Answer:** The digestive system is a group of organs (e.g., mouth, esophagus, stomach, intestines, liver, pancreas) that work together to break down food, absorb nutrients, and eliminate waste.
**25. What is called absorption?**
**Answer:** Absorption is the process by which digested nutrients pass through the intestinal lining into the bloodstream or lymphatic system for distribution to cells.
**26. What is called the secretion of salivary glands?**
**Answer:** Saliva. It contains water, electrolytes, mucus, and enzymes like amylase.
**27. Name the largest gland of the human body.**
**Answer:** The liver.
**28. Where is bile stored temporarily?**
**Answer:** In the gallbladder.
**29. Which gland of the body performs both exocrine and endocrine gland's function?**
**Answer:** The pancreas. It releases digestive enzymes (exocrine) and hormones like insulin (endocrine).
**30. What is called the secretion of the stomach?**
**Answer:** Gastric juice. It contains hydrochloric acid (HCl), pepsinogen (converted to pepsin), and mucus.
**31. What will be formed after partial digestion of protein in the stomach?**
**Answer:** Peptones (short polypeptide chains).
**32. Name the protein which is found in milk.**
**Answer:** Casein.
**33. Name the two protein-splitting enzymes found in pancreatic juice.**
**Answer:** Trypsin and chymotrypsin.
**34. Name the two carbohydrate-splitting enzymes found in pancreatic juice.**
**Answer:** Pancreatic amylase and pancreatic lipase (Note: Lipase digests fats, but maltase is a carbohydrate enzyme in the intestine).
**35. What is called assimilation?**
**Answer:** Assimilation is the process by which absorbed nutrients are incorporated into body tissues or used for energy production.
**36. Name one protein-splitting enzyme found in intestinal juice.**
**Answer:** Peptidase (e.g., aminopeptidase or dipeptidase).
**37. Name the salivary glands of the human body.**
**Answer:** Parotid, submandibular, and sublingual glands.
**38. Which component of food is digested in the buccal cavity?**
**Answer:** Carbohydrates (starch is partially digested by salivary amylase).
**39. What is called absorption? In which part of the intestine does maximum absorption occur?**
**Answer:** Absorption is the uptake of nutrients into the bloodstream. Maximum absorption occurs in the **small intestine** (specifically the jejunum and ileum).
**40. Write two major functions of the liver.**
**Answer:**
1. Production of bile for fat digestion.
2. Detoxification of harmful substances.
**41. Which component of food is digested in the stomach?**
**Answer:** Proteins (broken down by pepsin).
**42. Write two major functions of saliva.**
**Answer:**
1. Moistens food for easier swallowing.
2. Initiates starch digestion with salivary amylase.
**43. In which cells of plants do the reactions of photosynthesis occur?**
**Answer:** Mesophyll cells (specifically in chloroplasts).
**44. What is called photosynthetic autotrophs?**
**Answer:** Organisms that synthesize their own food using light energy (e.g., plants, algae, cyanobacteria).
**45. What is called chemosynthetic autotrophs?**
**Answer:** Organisms that produce food using energy from chemical reactions (e.g., sulfur bacteria in hydrothermal vents).
**46. What is called heterotrophs? Give an example.**
**Answer:** Organisms that rely on consuming other organisms for nutrients. Example: Humans, animals, fungi.
**47. What is called photosynthesis?**
**Answer:** The process by which green plants convert carbon dioxide and water into glucose and oxygen using sunlight.
**48. In photosynthesis, which particle of solar energy can be absorbed by photosynthetic pigments?**
**Answer:** Photons (light particles).
**49. What is called carbon fixation?**
**Answer:** The incorporation of atmospheric CO₂ into organic molecules (e.g., glucose) during the Calvin cycle.
**50. What is called stroma?**
**Answer:** The fluid-filled matrix in chloroplasts where the Calvin cycle occurs.
**51. What is called granum?**
**Answer:** A stack of thylakoid discs in chloroplasts, where light-dependent reactions occur.
**52. In the light reaction of photosynthesis, where is light energy stored in the form of chemical energy?**
**Answer:** In ATP and NADPH.
**53. In which reaction of photosynthesis does the synthesis of carbohydrates and organic compounds occur?**
**Answer:In the Calvin cycle of photosynthesis (light-independent/dark reaction).
54. What is called photosynthetic unit?
A photosynthetic unit is the group of pigment molecules that work together to harvest light energy during photosynthesis. It includes the reaction center and antenna pigments.
55. What is function of antenna pigment?
Antenna pigments capture light energy and transfer it to the reaction center chlorophyll to initiate the process of photosynthesis.
56. What is called photosystem?
A photosystem is a complex of chlorophyll molecules, proteins, and other pigments that participate in the light-dependent reactions of photosynthesis. There are two types: Photosystem I (PSI) and Photosystem II (PSII).
57. What is called photophosphorylation?
Photophosphorylation is the process of synthesizing ATP from ADP and inorganic phosphate using light energy during photosynthesis.
58. Write the wavelength of solar ray which can be trapped by photosystem-I.
Photosystem I absorbs light most efficiently at a wavelength of 700 nm (P700).
59. Write the wavelength of solar ray which can be trapped by photosystem-II.
Photosystem II absorbs light most efficiently at a wavelength of 680 nm (P680).
60. What is called photolysis of water?
Photolysis of water is the splitting of water molecules into oxygen, protons, and electrons using light energy, occurring in Photosystem II.
61. What is called carboxylation?
Carboxylation is the process of adding carbon dioxide to a compound, as in the first step of the Calvin cycle where CO₂ is fixed to RuBP.
62. Name the source of carbon of photosynthesis process.
The source of carbon in the photosynthesis process is carbon dioxide (CO₂) from the atmosphere.
63. The organisms which have the capacity to synthesize organic compounds from CO₂ and water. Such organisms are known as what?
Such organisms are known as autotrophs or photoautotrophs.
64. What is called the group of photosynthetic pigments?
The group of photosynthetic pigments includes chlorophylls, carotenoids, and phycobilins.
65. What is the main photosynthetic pigment of reaction centre?
Chlorophyll-a is the main photosynthetic pigment present in the reaction center.
66. What is the fate of carbohydrate which is produced during dark reaction of photosynthesis?
The carbohydrate produced (usually glucose) is used for energy, converted into other organic compounds, or stored as starch.
67. Which will provide the required energy for the conversion of PGA to PGAL?
ATP and NADPH, produced in the light reaction, provide the required energy and reducing power for this conversion.
68. Write the chemical reaction which occurs in aerobic respiration.
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (ATP)
69. What is the final product of glycolysis?
Pyruvic acid (or pyruvate) is the final product of glycolysis.
70. What is called respiration?
Respiration is the biochemical process by which cells break down glucose and other molecules to release energy.
71. Define cellular respiration.
Cellular respiration is the process by which cells convert glucose and oxygen into energy (ATP), carbon dioxide, and water.
72. What is the main aim of cellular respiration?
The main aim of cellular respiration is to produce ATP, the energy currency of the cell.
73. Why is respiration called catabolic process?
Respiration is called a catabolic process because it involves the breakdown of complex molecules like glucose into simpler molecules, releasing energy.
74. Name the process through which CO₂ is eliminated from the cell which is produced during respiration.
The process is called exhalation or expiration in higher organisms, and diffusion in unicellular organisms.
75. What are the different types of respiration based on the presence or absence of oxygen?
Aerobic respiration (with oxygen)
Anaerobic respiration (without oxygen)
76. Define glycolysis.
Glycolysis is the anaerobic process of breaking down glucose into pyruvate, producing a small amount of ATP and NADH.
77. What is called fermentation?
Fermentation is an anaerobic process where pyruvate is converted into other compounds like ethanol or lactic acid, producing ATP.
78. What type of fermentation takes place in muscle cell?
Lactic acid fermentation occurs in muscle cells during heavy exercise.
79. Write a similarities in between glycolysis and fermentation.
Both processes occur in the cytoplasm, are anaerobic, and involve the breakdown of glucose with the formation of ATP.
80. What is called external respiration?
External respiration is the exchange of gases (oxygen and carbon dioxide) between the environment and the blood through lungs or gills.
81. What is called internal respiration?
Internal respiration is the exchange of gases between blood and body tissues.
82. What is called respiratory system?
The respiratory system is the biological system consisting of organs and structures used for gas exchange.
83. Name the respiratory organ of annelida.
The skin acts as the respiratory organ in annelids like earthworms.
84. What is called respiration?
Respiration is the process by which organisms convert glucose into energy.
Here are the detailed answers along with the questions from the image you provided:
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85. Name the pigment of Red Blood corpuscle of blood which helps in conduction of oxygen and carbon dioxide.
Answer: Hemoglobin.
86. When the oxyhemoglobin dissociates?
Answer: Oxyhemoglobin dissociates in the tissues where oxygen concentration is low, releasing oxygen.
87. Name the smallest unit of respiratory system.
Answer: Alveolus.
88. Where is aerobic respiration occurs in a cell?
Answer: In the mitochondria.
89. Why is exchange of O₂ and CO₂ occurs in between alveoli of lungs and blood capillaries?
Answer: Because of the difference in partial pressures (concentration gradient) of gases between alveoli and blood.
90. What is called Kreb's cycle?
Answer: Kreb's cycle, also known as the citric acid cycle, is a series of chemical reactions in the mitochondria that generate energy through the oxidation of acetyl-CoA.
91. Name the substances which are produced during respiration.
Answer: Carbon dioxide, water, and energy (ATP).
92. Write the full name of ATP.
Answer: Adenosine Triphosphate.
93. Name the substances which are produced during anaerobic respiration.
Answer: Lactic acid (in animals) or ethanol and carbon dioxide (in yeast), and a small amount of ATP.
94. Write the reaction which occurs in anaerobic respiration of yeast.
Answer: Glucose → Ethanol + Carbon dioxide + Energy (ATP)
95. Name one animal which obtain energy through anaerobic respiration of yeast.
Answer: Yeast itself is not an animal. However, some animals like earthworms and human muscles (temporarily) use anaerobic respiration.
96. During heavy exercise what will be produced in addition to ATP?
Answer: Lactic acid.
97. Write the chemical reaction which occurs in aerobic respiration.
Answer: Glucose + Oxygen → Carbon dioxide + Water + Energy (ATP)
98. Name the extracellular enzyme which is concerned with anaerobic respiration of yeast.
Answer: Zymase.
99. Name two animals which can respire through skin.
Answer: Earthworm and leech.
100. Name the respiratory organ of prawn.
Answer: Gills.
101. Name the respiratory organ of amoeba.
Answer: Cell membrane (respiration occurs through diffusion).
102. Why is oxygen essential for us?
Answer: Oxygen is essential for aerobic respiration which produces energy in the form of ATP.
103. What will be the product of anaerobic respiration?
Answer: In animals: Lactic acid.
In yeast: Ethanol and carbon dioxide.
104. What are the raw materials of plant respiration?
Answer: Glucose and oxygen.
105. What are the products of plant respiration?
Answer: Carbon dioxide, water, and energy (ATP).
106. How is the leaves of plant can absorb essential oxygen?
Answer: Through the stomata by diffusion.
107. Write the role of stomata in the process of photosynthesis and respiration of plants.
Answer: Stomata allow gas exchange; they take in CO₂ for photosynthesis and release O₂, and also allow O₂ intake and CO₂ release during respiration.
108. Define ascent of sap.
Answer: The upward movement of water and minerals from roots to leaves through xylem.
109. Which vascular bundle transport organic compound?
Answer: Phloem.
110. Name four essential salts of plant nutrition.
Answer: Nitrates, phosphates, potassium salts, and magnesium salts.
111. Why is NaCl found as Na⁺ and Cl⁻ ion in soil?
Answer: Because it dissociates into ions in the presence of water.
112. Why is the salts of soil not enters into the roots of plant by simple diffusion?
Answer: Due to selective permeability of the root cell membranes and active transport mechanisms.
Here are the answers to the questions from the image provided:
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113. What is plant vascular tissue?
Plant vascular tissue consists of xylem and phloem, which help in the transport of water, minerals, and food in plants.
114. Name the tissue of plant through which translocation of food occurs.
Phloem is the tissue responsible for the translocation of food in plants.
115. Name the tissues of plant body which control the internal circulation of plant.
Xylem and phloem control the internal circulation of water, minerals, and food in plants.
116. What is called pericardial cavity?
The pericardial cavity is the space between the layers of the pericardium (a membrane enclosing the heart), which contains pericardial fluid to reduce friction.
117. Define circulatory system.
The circulatory system is the system responsible for the transport of blood, nutrients, gases, and wastes throughout the body.
118. Name the circulatory system which transports nitrogenous excretory substances to the kidney.
The excretory part of the circulatory system, especially the renal circulation, helps transport waste materials to the kidneys.
119. What are the divisions of human circulatory system?
The human circulatory system is divided into the pulmonary circulation and the systemic circulation.
120. What is the medium of blood vascular system?
Blood is the medium of the blood vascular system.
121. Where is the human heart lies?
The human heart lies in the thoracic cavity between the two lungs, slightly to the left of the center.
122. What is called cardiac muscle?
Cardiac muscle is a type of involuntary muscle found only in the heart, responsible for the pumping action of the heart.
123. How many auricles and ventricles are found in human heart?
There are two auricles (atria) and two ventricles in the human heart.
124. Why is the blood not back flow to vena cava?
The blood does not flow back to the vena cava due to the presence of valves that prevent backflow.
125. The blood enters into ventricles from auricles but not back flow to auricles. Why?
This is because of the presence of atrioventricular valves (tricuspid and bicuspid/mitral) that prevent the backflow of blood from ventricles to auricles.
126. Why is blood of systemic aorta and pulmonary aorta not back flow to ventricles?
The semilunar valves at the base of the aorta and pulmonary artery prevent backflow of blood into the ventricles.
127. Where is the deoxygenated blood found in human heart?
Deoxygenated blood is found in the right atrium and right ventricle of the heart.
128. Where is the oxygenated blood found in human heart?
Oxygenated blood is found in the left atrium and left ventricle of the heart.
129. From which part of human heart systemic aorta arises?
The systemic aorta arises from the left ventricle.
130. From which part of human heart pulmonary aorta arises?
The pulmonary aorta (pulmonary artery) arises from the right ventricle.
131. What is called plasma?
Plasma is the liquid component of blood that holds the blood cells in suspension and transports nutrients, hormones, and waste products.
132. Write one important function of red blood cell.
Red blood cells transport oxygen from the lungs to the body tissues and carry carbon dioxide back to the lungs.
133. Name the white blood cell which helps in the formation of antibody.
Lymphocytes (a type of white blood cell) help in the formation of antibodies.
134. Write one important function of platelets.
Platelets help in the clotting of blood, preventing excessive bleeding.
135. Define homeostasis.
Homeostasis is the process by which an organism maintains a stable internal environment despite external changes.
136. What is called artery?
An artery is a blood vessel that carries blood away from the heart.
137. What is called vein?
A vein is a blood vessel that carries blood toward the heart.
138. What is called venous system?
The venous system is the network of veins that return deoxygenated blood from the body to the heart.
139. Name the artery which carries deoxygenated blood?
The pulmonary artery carries deoxygenated blood from the heart to the lungs.
140. Name the vein which carries oxygenated blood?
The pulmonary vein carries oxygenated blood from the lungs to the heart.
Here are the detailed answers to the questions from the image you provided:
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141. What is lymph?
Lymph is a clear fluid that circulates in the lymphatic system and contains white blood cells, especially lymphocytes.
142. Write one function of lymph.
It helps in the transportation of fats from the digestive system and also plays a role in immune defense.
143. Name the structural muscle of heart.
Cardiac muscle.
144. Write down two functions of plasma.
1. Transports nutrients, hormones, and proteins to parts of the body.
2. Helps in the removal of waste products.
145. Name the membrane which separates the right auricle and left auricle.
Interatrial septum.
146. Name the chambers of human heart.
Right atrium, right ventricle, left atrium, and left ventricle.
147. In which chamber of human heart blood supplies through venacava?
Right atrium.
148. Name the two valves which are found in between right auricle and ventricle and in between left auricle and ventricle.
Ans:
1. Tricuspid valve (right side).
2. Bicuspid or mitral valve (left side).
149. What is the main function of animal circulatory system?
To transport nutrients, gases, and wastes to and from the cells of the body.
150. Write two main functions of animal circulatory system.
Ans:
1. Transportation of oxygen and nutrients to tissues.
2. Removal of carbon dioxide and metabolic wastes.
151. Where is pericardial fluid found and what is the function of it?
It is found between the pericardial membranes of the heart. It reduces friction during heartbeats.
152. Name the two venacava which carries deoxygenated blood from different parts of the body to heart.
Ans:
1. Superior vena cava.
2. Inferior vena cava.
153. Name the two aorta which carries blood from heart to lungs and different parts of the body.
Ans:
1. Pulmonary artery (to lungs).
2. Aorta (to body).
154. Mention two major functions of blood.
Ans:
1. Transportation of gases, nutrients, and waste.
2. Regulation of body temperature and pH balance.
155. What is the main function of red blood cell?
To carry oxygen from lungs to tissues and return carbon dioxide from tissues to lungs.
156. Name the respiratory pigment which is found in red blood cell.
Hemoglobin.
157. Name two mammals which have nucleated red blood cell.
Most mammals have non-nucleated red blood cells. However, fetal red blood cells and those in certain disease conditions may retain nuclei.
158. What is nephron?
It is the structural and functional unit of the kidney that filters blood to form urine.
159. What is the primary unit of human kidney?
Nephron.
160. What is called excretion?
The process of removal of metabolic waste products from the body.
161. What are the divisions of excretory product?
Ans:
1. Nitrogenous wastes (urea, ammonia, uric acid).
2. Carbon dioxide.
3. Water and salts.
162. Name two nitrogenous excretory substances of our body.
Ans:
1. Urea.
2. Creatinine.
163. Name the nitrogenous excretory substance of aquatic animal.
Ammonia.
164. What is the nitrogenous excretory substance of tadpole?
Ammonia (as it is aquatic in nature).
165. In animal body uric acid may be deposited but ammonia and urea can not be deposited in the body, why?
Ammonia and urea are toxic and highly soluble in water, so they must be excreted immediately. Uric acid is less toxic and can be stored in the body as crystals.
166. What is the nitrogenous excretory substance of bird?
Ans: Uric acid .
167. What is called glomerulus?
Answer: Glomerulus is a network of capillaries located at the beginning of a nephron in the kidney. It is responsible for the filtration of blood to form urine.
168. What is the main function of kidney?
Answer: The main function of the kidney is to filter waste products and excess substances from the blood to form urine. It also helps regulate blood pressure, electrolyte balance, and red blood cell production.
169. What is called Malpighian corpuscle?
Answer: A Malpighian corpuscle, also known as a renal corpuscle, consists of the glomerulus and Bowman's capsule. It is involved in the filtration of blood in the kidney.
170. Name two glands which are found in human skin.
Answer: The two glands found in human skin are:
1. Sweat glands
2. Sebaceous glands
171. Write the function of lungs as an excretory organ.
Answer: Lungs act as excretory organs by removing carbon dioxide, a waste product of respiration, from the body through exhalation.
172. What is called deamination?
Answer: Deamination is the process of removing the amino group from an amino acid, converting it into ammonia and a keto acid. This occurs mainly in the liver.
173. Name two bile pigments.
Answer: The two bile pigments are:
1. Bilirubin
2. Biliverdin
174. Write down two chief excretory products of human body.
Answer: The two chief excretory products of the human body are:
1. Urea
2. Carbon dioxide
175. Name the nitrogenous excretory substances which are found in animal body.
Answer: The nitrogenous excretory substances found in animals include:
1. Urea
2. Uric acid
3. Ammonia
176. Write down various parts of human excretory system.
Answer: The main parts of the human excretory system are:
1. Kidneys
2. Ureters
3. Urinary bladder
4. Urethra
177. What are the two major parts of nephron?
Answer: The two major parts of a nephron are:
1. Renal corpuscle (glomerulus + Bowman's capsule)
2. Renal tubule (proximal convoluted tubule, loop of Henle, distal convoluted tubule)
178. Name the other excretory organs of mammal other than kidney.
Answer: Other excretory organs besides the kidney include:
1. Lungs (excrete CO₂)
2. Skin (sweat glands excrete salts and water)
3. Liver (breaks down toxins)
4. Large intestine (eliminates undigested waste)
179. “All plants give out oxygen during day and carbon dioxide during night.” Do you agree with this statement? Give reason.
Answer: Yes, this statement is correct. During the day, plants perform photosynthesis, using carbon dioxide and releasing oxygen. At night, in the absence of sunlight, photosynthesis stops, and plants respire like animals, taking in oxygen and releasing carbon dioxide.
180. What would happen if green plants disappear from earth?
Answer: If green plants disappeared from Earth:
- Oxygen levels would drop, making survival difficult for most living organisms.
- The food chain would collapse, as plants are the primary producers.
- Carbon dioxide levels would increase, leading to global warming.
- Ecosystems would be destroyed.
181. Name the part of the brain which controls breathing.
Answer: The medulla oblongata, part of the brainstem, controls the involuntary process of breathing.
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B. Short Type Questions:
1. What is the significance of emulsification of fats?
Answer:
Emulsification of fats is the process by which large fat globules are broken down into smaller droplets. This increases the surface area for the action of the enzyme lipase, which digests fats. It is an important step in fat digestion and is carried out by bile salts released from the liver.
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2. What is the advantage of having a four-chambered heart?
Answer:
A four-chambered heart ensures complete separation of oxygenated and deoxygenated blood. This allows efficient circulation of oxygen-rich blood to body tissues, which is crucial for warm-blooded animals (like birds and mammals) to maintain a constant body temperature and high metabolic activity.
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3. In each of the following situations, what happens to the rate of photosynthesis?
(a) Cloudy days:
The rate of photosynthesis decreases due to reduced sunlight, which is essential for the process.
(b) No rainfall in the area:
Photosynthesis slows down due to water deficiency, as water is a raw material for the process.
(c) Good manuring in the area:
Photosynthesis increases as nutrients from manure promote healthy plant growth and function.
(d) Stomata get blocked due to dust:
Photosynthesis decreases because stomata are essential for gas exchange (CO₂ intake).
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4. Why do veins have thin walls as compared to arteries?
Answer:
Veins carry blood at a lower pressure compared to arteries, so they do not need thick muscular walls. Instead, their thin walls and valves help in the return of blood to the heart, especially from the lower parts of the body.
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5. What will happen if platelets were absent in the blood?
Answer:
If platelets were absent, blood clotting would not occur properly. This would result in excessive bleeding even from small injuries, as the clotting process helps seal wounds and prevent blood loss.
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6. What is called autotrophic nutrition? In which organisms autotrophic nutrition takes place?
Answer:
Autotrophic nutrition is a mode of nutrition in which organisms prepare their own food using simple substances like carbon dioxide and water in the presence of sunlight and chlorophyll (e.g., photosynthesis). This type of nutrition takes place in green plants, algae, and some bacteria.
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7. What is called autotrophs and heterotrophs? Give examples.
Answer:
Autotrophs are organisms that can prepare their own food from simple substances (e.g., green plants, algae).
Heterotrophs are organisms that depend on other organisms for food (e.g., animals, fungi, humans).
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8. What is called heterotrophic nutrition? What is called consumer? Give examples.
Answer:
Heterotrophic nutrition is the mode of nutrition in which organisms obtain food from other organisms because they cannot synthesize their own food.
Consumers are organisms that depend on other organisms for food.
Examples: Humans, animals, fungi, etc.
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9. In which types of nutrition, animals feed solid food? In case man what type of nutrition occurs?
Answer:
Animals feed on solid food in holozoic nutrition.
In humans, holozoic nutrition also occurs, which involves ingestion, digestion, absorption, assimilation, and egestion.
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10. Write down different types of salivary glands found in human body and write their functions.
Answer:
Three types of salivary glands:
1. Parotid glands – secrete watery saliva rich in enzymes.
2. Submandibular glands – secrete both enzymes and mucus.
3. Sublingual glands – secrete mostly mucus.
Function: Saliva moistens food, helps in digestion by breaking starch with salivary amylase, and aids in swallowing.
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11. Mention any four functions of saliva.
Answer:
1. Moistens food.
2. Helps in digestion of starch.
3. Aids in swallowing.
4. Maintains oral hygiene and pH.
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12. Name the juice, which is secreted by liver.
Answer:
Bile juice is secreted by the liver.
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13. Write the functions of liver.
Answer: The functions of liver are-
1. Secretion of bile juice.
2. Detoxification of harmful substances.
3. Storage of glucose as glycogen.
4. Synthesis of proteins and fats.
5. Breakdown of old red blood cells.
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14. In which exocrine gland: (a) Glucose is converted into glycogen (b) Ammonia is converted into urea.
Answer:
(a) Liver converts glucose into glycogen.
(b) Liver converts ammonia into urea.
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15. Which part of food is digested in buccal cavity? How it occurs?
Answer:
Starch is digested in the buccal cavity by the enzyme salivary amylase, which converts starch into maltose.
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16. Which part of food is digested in stomach? How it occurs?
Answer:
Proteins are digested in the stomach.
Gastric juice contains pepsin which breaks down proteins into peptides.
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17. Write two functions of bile salts.
Answer: The two functions are-
1. Emulsify fats (break large fat globules into smaller ones).
2. Neutralize the acidic food from the stomach.
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18. Write the role of pancreatic juice in the digestion of protein in small intestine of alimentary canal.
Answer:
Pancreatic juice contains trypsin, which breaks down proteins into smaller peptides in the small intestine.
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19. Write the role of pancreatic juice in the digestion of carbohydrate in small intestine of alimentary canal.
Answer:
Pancreatic juice contains amylase, which converts starch into maltose in the small intestine.
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20. Write the functions of intestinal juice in the digestion of protein in small intestine.
Answer:
Intestinal juice contains peptidases, which break down peptides into amino acids.
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21. What are the main parts of alimentary canal?
Answer: The main parts include:
1. Mouth
2. Pharynx
3. Esophagus
4. Stomach
5. Small intestine
6. Large intestine
7. Rectum
8. Anus
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22. Match the Group -A with Group -B.
Ans:
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23. In photosynthesis, why is water known as reactant?
Answer:
Water provides hydrogen ions and electrons during photosynthesis. It is split during the light reaction to release oxygen, thus it acts as a reactant.
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24. Name the pigments which are found in chlorophyll? Which pigment takes part in photosynthesis?
Answer:
Pigments are:
- Chlorophyll ( a)
- Chlorophyll ( b)
- Xanthophyll
- Carotene
Chlorophyll a is the main pigment that takes part in photosynthesis.
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25. What do you mean by plant circulation?
Answer:
Plant circulation refers to the transport of water, minerals, and food through xylem and phloem tissues in plants.
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26. What do you mean by circulatory system of organisms?
Answer:
The circulatory system is the organ system that transports blood, nutrients, gases, and wastes throughout the body.
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27. Write the wave length of light which is absorbed and radiated by chlorophyll and carotenoid pigments.
Answer:
Chlorophyll absorbs light mostly in the blue (430–450 nm) and red (640–680 nm) regions.
Carotenoids absorb in the blue (400–500 nm) region.
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28. What is called photosynthetic unit? What is the meaning of it?
Answer:
The photosynthetic unit is the group of chlorophyll molecules that absorb
light and transfer energy to the reaction center. It refers to a functional unit involved in light absorption and energy transfer during photosynthesis.
28. Write down the name of important materials made of carbohydrates which is produced by the plants.
Answer: Starch and cellulose are important materials made of carbohydrates produced by plants.
29. Name the plant body carbohydrate which is synthesized during photosynthesis.
Answer: Glucose is the plant body carbohydrate synthesized during photosynthesis.
30. Why is photosynthesis most essential for the living world?
Answer: Photosynthesis is essential as it provides oxygen for respiration and organic food (glucose) that supports the base of the food chain.
31. Draw a neat labeled diagram of chloroplast.
Answer: (This requires a diagram. You would draw a typical chloroplast showing structures like thylakoid, stroma, granum, inner and outer membranes.)
32. Write the role of chloroplast in photosynthesis.
Answer: Chloroplasts contain chlorophyll which captures light energy and converts it into chemical energy during photosynthesis.
33. Which part of thylakoid describes briefly the structure of thylakoid?
Answer: Thylakoids are membrane-bound compartments inside chloroplasts, arranged in stacks called grana; they house the photosynthetic pigments and are the site of the light-dependent reactions.
34. Matching the following:
- (a) Chemosynthetic autotrophs → (iii) Trap solar energy
- (b) Photosynthetic autotrophs → (iv) Use energy from chemical reaction
- (c) NADPH → (i) Accepts electrons during photosynthesis
- (d) Chloroplasts → (ii) Site of photosynthesis
Correct matching:
- (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii)
35. What are the different types of essential nutrient elements based on their necessity?
Answer: Essential nutrients are classified as macronutrients (needed in large amounts) like nitrogen, phosphorus, potassium; and micronutrients (needed in small amounts) like iron, zinc, manganese.
36. The carnivorous plants can perform photosynthesis although they are considered so omnivorous, why?
Answer: Carnivorous plants perform photosynthesis like other green plants to produce food, but they supplement their nutrient intake, especially nitrogen, by digesting insects.
37. Exogenous supply of starch is detected after some days if plants have a lack of starch. Why?
Answer: Starch is produced internally through photosynthesis. If starch is lacking, it indicates that photosynthesis is not occurring effectively, requiring external (exogenous) supply.
38. Write the significance of photosynthesis.
Answer: Photosynthesis provides oxygen, forms the base of food chains by producing glucose, and removes carbon dioxide from the atmosphere.
39. Write short notes on:
(a) Chloroplast
Answer: Chloroplasts are organelles in plant cells containing chlorophyll, where photosynthesis takes place.
(b) Light reaction
Answer: The light reaction occurs in the thylakoid membranes and involves the conversion of light energy into chemical energy (ATP and NADPH).
(c) Non-cyclic photophosphorylation
Answer: This is the main pathway of the light reaction where electrons flow from water to NADP+, forming ATP and NADPH, and releasing oxygen.
40. Write the full name of the following:
(a) RuBP → Ribulose-1,5-bisphosphate
(b) NADPH → Nicotinamide Adenine Dinucleotide Phosphate (Reduced form)
(c) PGA → 3-Phosphoglyceric acid
41. Name the following:
(a) Flowering saprophytic plants → Monotropa (Indian Pipe)
(b) Nepenthes → A genus of carnivorous plants, also known as pitcher plants
42. Describe the electron transport system during photosynthesis.
Answer: The electron transport system (ETS) in photosynthesis occurs in the thylakoid membrane. It involves the transfer of electrons from water through photosystem II, plastoquinone, cytochrome complex, plastocyanin, and photosystem I to NADP+, forming NADPH. This transport also helps pump protons, leading to ATP synthesis via chemiosmosis.
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43. What is Calvin cycle? Describe briefly the Calvin cycle.
Answer: The Calvin cycle is the set of light-independent reactions in photosynthesis that take place in the stroma of chloroplasts. It uses ATP and NADPH produced in the light reactions to convert CO₂ into glucose.
Steps:
1. Carbon Fixation: CO₂ combines with RuBP (Ribulose bisphosphate) to form 3-PGA.
2. Reduction: ATP and NADPH reduce 3-PGA to G3P.
3. Regeneration: Some G3P forms glucose; others regenerate RuBP.
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44. What is fermentation?
Answer: Fermentation is an anaerobic process where energy is released from glucose without using oxygen. It occurs in yeast, bacteria, and muscle cells. It produces either alcohol (ethanol) or lactic acid and small amounts of ATP.
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45. What is called alcoholic fermentation?
Answer: Alcoholic fermentation is a process by which yeast converts sugars into ethanol and carbon dioxide under anaerobic conditions.
Equation:
Glucose → Ethanol + CO₂ + Energy (ATP)
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46. Describe briefly the mechanism of breath.
Answer: Breathing involves two phases:
Inhalation: Diaphragm contracts, chest cavity expands, air flows in.
Exhalation: Diaphragm relaxes, chest contracts, air is pushed out.
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47. Describe the exchange of respiratory gases in between alveoli of lungs and blood.
Answer:
Oxygen diffuses from alveoli into capillary blood due to higher concentration in alveoli.
Carbon dioxide diffuses from blood into alveoli due to higher concentration in blood.
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48. What are called fermentation and respiration?
Answer:
Fermentation: Anaerobic breakdown of glucose producing ATP without oxygen.
Respiration: Process of breaking down glucose to release energy, mostly aerobic (with oxygen).
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49. Write two main distinguishing features in between aerobic and anaerobic respiration.
Answer:
1. Oxygen Use: Aerobic uses oxygen; anaerobic does not.
2. ATP Yield: Aerobic yields more ATP (~38); anaerobic yields less (~2).
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50. Between boys and girls who have higher rate of respiration?
Answer: Typically, boys have a slightly higher rate due to greater muscle mass and energy needs, though it also depends on age and activity level.
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51. What is called cellular respiration? Describe briefly the cellular respiration in which occurs in muscle due to heavy exercise.
Answer: Cellular respiration is the process by which cells release energy from glucose.
During heavy exercise, muscle cells perform anaerobic respiration, producing lactic acid due to insufficient oxygen.
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52. Write the mechanism of external respiration.
Answer:
External respiration involves gas exchange between the lungs and blood:
- Oxygen from alveoli enters blood.
- Carbon dioxide from blood enters alveoli to be exhaled.
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53. Describe briefly the aerobic respiration.
Answer:
Aerobic respiration is the breakdown of glucose in the presence of oxygen to release energy.
Equation:
Glucose + O₂ → CO₂ + H₂O + Energy (ATP)
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54. What is glycolytic pathway of cellular respiration?
Answer:
The glycolytic pathway (glycolysis) is the first step of respiration, occurring in the cytoplasm.
Glucose (6C) → 2 Pyruvate (3C) + 2 ATP + 2 NADH
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55. Describe the transportation of oxygen through blood.
Answer:
Oxygen binds to hemoglobin in red blood cells, forming oxyhemoglobin. It is transported via blood to body tissues, where it is released.
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56. What is called alcohol produced during cellular respiration of yeast?
Answer: The alcohol is ethanol, produced during alcoholic fermentation in yeast.
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57. Why human muscle may fatigue after heavy exercise?
Answer: Due to lactic acid accumulation from anaerobic respiration when oxygen supply is low, causing muscle soreness and fatigue.
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58. Write the different stages of aerobic respiration.
Answer:
1. Glycolysis (cytoplasm)
2. Krebs Cycle (mitochondria)
3. Electron Transport Chain (ETC) (mitochondrial membrane)
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59. Write the chemical reactions of aerobic respiration.
Answer:
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy (ATP)
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60. Write the following: (a) Aerobic respiration of yeast. (b) Anaerobic respiration of muscle cell.
Answer:
(a) Aerobic (yeast): Glucose + O₂ → CO₂ + H₂O + Energy
(b) Anaerobic (muscle): Glucose → Lactic acid + Energy
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61. Distinguish between: (a) Lactic acid fermentation and alcoholic fermentation
Answer:
Lactic Acid Fermentation:
1. Occurs in muscle cells (during heavy exercise) and certain bacteria.
2. Takes place in the absence of oxygen (anaerobic conditions).
3. End product is lactic acid.
4. Produces a small amount of energy (2 ATP).
5. No carbon dioxide (CO₂) is released.
6. Common in yogurt production and during muscle fatigue.
Alcoholic Fermentation:
1. Occurs in yeast and some bacteria.
2. Also occurs in the absence of oxygen (anaerobic conditions).
3. End products are ethanol (alcohol) and carbon dioxide (CO₂).
4. Produces a small amount of energy (2 ATP).
5. Carbon dioxide (CO₂) is released.
6. Common in bread making and alcoholic beverages production.
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62. How respiration and photosynthesis are interdependent?
Answer:
Photosynthesis produces glucose and oxygen used in respiration.
Respiration releases CO₂ and water used in photosynthesis.
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63. How and where the plant can absorb oxygen for respiration?
Answer:
Plants absorb oxygen through stomata (leaves) and lenticels (stems) for respiration. Roots also absorb dissolved oxygen from soil.
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64. How and from where the leaves of plant can absorb oxygen for respiration?
Answer: Leaves absorb oxygen through tiny pores called stomata present on their surface. During respiration, oxygen diffuses in through these pores and is used to break down glucose for energy.
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65. Write the name of different types of transpiration.
Answer: There are three types of transpiration:
1. Stomatal transpiration – through stomata (most common).
2. Cuticular transpiration – through the cuticle layer of leaves.
3. Lenticular transpiration – through lenticels in stems.
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66. Write the name of different plant organs through which transpiration takes place? Is transpiration essential for plants?
Answer:
Organs involved in transpiration:
Leaves (mainly through stomata)
Stems (through lenticels)
Cuticle (outer surface of leaves)
Importance of transpiration:
Helps in upward movement of water (ascent of sap)
Maintains temperature
Supplies water and minerals to plant parts
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67. Write the structure of stomata with diagram.
Answer: Stomata consist of:
- Guard cells – kidney-shaped cells that regulate opening/closing
- Stomatal pore – the opening between guard cells
- Subsidiary cells – support guard cells
Diagram
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68. Write the significance of transpiration.
Answer: The significance of transpiration are-
- Helps in water absorption and transport
- Maintains leaf temperature
- Aids in nutrient distribution
- Maintains turgor pressure in cells
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69. What is called epidermal transpiration?
Answer:
Transpiration that occurs through the epidermal layer of leaves, particularly through cuticle and stomata, is called epidermal transpiration.
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70. What are the merits of transpiration?
Answer:
The merits of transpiration are-
- Aids in cooling the plant
- Enables upward movement of water (pull force)
- Facilitates nutrient transport
- Maintains turgidity of cells
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71. What are the demerits of transpiration?
Answer: The demerits of transpiration are-
- Excessive transpiration may cause wilting
- Water loss during drought conditions can be harmful
- Reduces water availability for growth
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72. What is called circulatory system?
Answer:
A circulatory system is a system in living organisms that circulates blood and lymph through the body, delivering nutrients, gases, and removing wastes. In humans, it includes the heart, blood vessels, and blood.
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73. Define cyclosis.
Answer:
Cyclosis is the movement of cytoplasm within a cell that helps in the distribution of nutrients, organelles, and other substances.
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74. What is called imbibition?
Answer:
Imbibition is the absorption of water by solid particles of a substance without forming a solution, e.g., dry seeds absorbing water.
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75. Define osmosis.
Answer:
Osmosis is the movement of water molecules from a region of higher water concentration to lower concentration through a semi-permeable membrane.
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76. What is called diffusion?
Answer:
Diffusion is the movement of molecules or particles from an area of high concentration to low concentration until equilibrium is reached.
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77. Write two differences between artery and vein.
Answer:
| Artery | Vein |
| Carries blood away from the heart | Carries blood to the heart |
| Thick and elastic walls | Thin walls with valves |
| Blood under high pressure | Blood under low pressure |
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78. Write the functions of blood. (HSLC ’08)
Answer: The functions of blood:
- Transport of oxygen and nutrients
- Removal of carbon dioxide and waste
- Defense against infections
- Regulation of body temperature
- Blood clotting to prevent loss
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79. Name the pigment which is found in blood? Write about exchange of respiratory gases in between blood and alveoli with diagram.
Answer:
Pigment: Hemoglobin
Gas exchange: Oxygen from alveoli diffuses into the blood
Carbon dioxide from blood diffuses into alveoli
Hemoglobin binds with oxygen to form oxyhemoglobin
Diagram typically shows alveoli with capillaries around it
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80. Name the valves which are found in between right auricle and ventricle; left auricle and ventricle. Write the function of these two.
Answer:
Right side valve: Tricuspid valve
Left side valve: Bicuspid (mitral) valve
Function: Prevents backflow of blood from ventricle to auricle
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81. What is inspiration? What role plays by the intercostal muscle during respiration?
Answer:
Inspiration is the process of inhaling air into the lungs.
Intercostal muscles contract, lifting the ribs up and out, expanding chest cavity and allowing lungs to fill with air.
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82. What are the structural components of lymphatic system? Write one function of it.
Answer:
Components:
Lymph
Lymph vessels
Lymph nodes
Function: Returns excess tissue fluid to bloodstream and helps in immunity.
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83. Write briefly about the internal structure of human heart.
Answer:
4 chambers: Right atrium, right ventricle, left atrium, left ventricle
Separated by valves: Tricuspid, bicuspid, pulmonary, aortic
Pumps blood to lungs and rest of the body
Right side: deoxygenated blood; Left side: oxygenated blood
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84. Name the venacava which carries blood from upper part of the body to heart and lower part of body to heart.
Answer:
Superior vena cava – from upper body
Inferior vena cava – from lower body
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85. Write the composition of plasma.
Answer:
Plasma contains:
Water (90-92%)
Proteins (albumin, globulin, fibrinogen)
Salts, hormones, glucose, waste products
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86. How is blood coagulated? Name the blood cell which helps in blood clotting.
Answer:
Clotting process: Platelets release chemicals that activate clotting factors; fibrin forms a mesh to stop bleeding.
Cell involved: Platelets (thrombocytes)
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87. What are the necessity of circulatory system in higher animals?
Answer:
Transport of gases, nutrients, hormones
Waste removal
Protection (immune cells)
Temperature regulation
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88. Distinguish between –
(a) Blood and lymph:
Blood: red, contains RBCs, circulates via heart
Lymph: colorless, lacks RBCs, part of lymphatic system
(b) Blood vascular system and lymphatic system:
Blood vascular: heart, arteries, veins, blood
Lymphatic: lymph nodes, vessels, lymph
(c) Internal structure of right and left auricle:
Right auricle: receives deoxygenated blood from body
Left auricle: receives oxygenated blood from lungs
Thinner walls in right auricle compared to left
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Here are the detailed questions and answers from the image you provided (Questions 89 to 108):
89. Name the excretory organ of higher and lower animals through which they can eliminate carbon dioxide.
Answer:
- Higher animals (e.g., mammals): Lungs eliminate carbon dioxide.
- Lower animals (e.g., amoeba, hydra): Cell membrane or body surface helps in CO₂ elimination through diffusion.
90. Write four functions of excretory organ.
Answer:
- Removal of metabolic waste products (like urea, uric acid).
- Regulation of water and salt balance (osmoregulation).
- Maintenance of acid-base balance in the body.
- Secretion of certain hormones (e.g., erythropoietin by kidneys).
91. Mention the different parts of excretory system of vertebrate animals.
Answer:
- Kidneys
- Ureters
- Urinary bladder
- Urethra
92. Draw a neat labelled diagram of human excretory system.
Answer:
A diagram should include: Kidneys, Ureters, Urinary Bladder, Urethra.
93. Draw a neat labelled diagram of internal structure of human kidney.
Answer:
The diagram should include: Cortex, Medulla, Renal pelvis, Nephrons, etc.
(I can generate this image for you if needed.)
94. Write briefly about the internal structure of human kidney.
Answer:
Each kidney is made of an outer cortex and an inner medulla. The medulla has pyramids which drain into calyces and then into the renal pelvis. The functional units are nephrons, consisting of glomerulus, Bowman’s capsule, and renal tubules.
95. How is reabsorption occurs in nephric tubule?
Answer:
Reabsorption in the nephric tubule occurs mainly in the proximal convoluted tubule. Essential substances like glucose, amino acids, water, and salts are reabsorbed into the blood via active and passive transport.
96. What is called nephric tubular secretion?
Answer:
Tubular secretion is the process where substances like hydrogen ions, potassium ions, and certain drugs are actively secreted from blood into the renal tubule for elimination.
97. Skin as an excretory organ. Explain.
Answer:
Skin excretes waste through sweat glands, which remove water, salts, and urea. It also helps regulate body temperature.
98. Liver as an excretory organ. Explain.
Answer:
Liver breaks down hemoglobin to form bilirubin and biliverdin, which are excreted via bile. It also detoxifies harmful substances and excretes cholesterol and other wastes.
99. Write the name of different parts of nephron.
Answer:
- Bowman’s capsule
- Proximal convoluted tubule
- Loop of Henle
- Distal convoluted tubule
- Collecting duct
100. Draw a neat labelled diagram of Malpighian corpuscle.
Answer:
101. (i) Label any four parts in the given diagram. (ii) What are the two functions represented in this diagram?
Answer:
(This refers to a diagram not shown in the image. Likely a nephron or excretory system.)
- Four parts may include: Glomerulus, Bowman’s capsule, Tubule, Collecting duct.
- Two functions: Filtration and Reabsorption.
102. In the experiment to show that CO₂ is given out during respiration, the student uses–
Answer:
Correct option: (a) Lime water – It turns milky in presence of CO₂.
103. State the name and function of acid produced in our stomach. What remedy would you suggest to a person suffering from indigestion, pain and irritation in the stomach? Name the main ingredient of this remedy and state its function.
Answer:
- Acid: Hydrochloric acid (HCl)
- Remedy: Antacid (e.g., milk of magnesia)
- Main ingredient: Magnesium hydroxide – It neutralizes excess acid.
104. (a) Fresh milk has pH when it changes into curd will its pH value increase or decrease?
Answer:
pH will decrease as curd is more acidic due to lactic acid.
(b) What will happen to a plant if its xylem is removed?
Answer:
- The plant will wilt and die due to lack of water and mineral transport.
105. What is meant by breathing? What happen to the rate of breathing during vigorous exercise and why?
Answer:
- Breathing: Process of inhaling oxygen and exhaling carbon dioxide.
- During vigorous exercise, the rate of breathing increases to supply more oxygen and remove CO₂ due to increased energy demand.
106. Define translocation with respect to transport in plants. Why is it essential for plants? Where in plants are the following synthesized? (i) Sugar (ii) Hormone
Answer:
- Translocation: Movement of food substances (like sugars) from leaves to other parts via phloem.
- Essential for growth, storage, and metabolism.
- Sugar is synthesized in leaves (photosynthesis).
- Hormones are synthesized in meristematic tissues, roots, and leaves.
107. What is the function of the trachea? Why do its walls not collapse even when there is less air in it?
Answer:
- Trachea transports air to and from lungs.
- Its walls do not collapse due to C-shaped cartilage rings that provide structural support.
108. Stomata of desert plants remain closed during day time. How do they take up carbon dioxide and perform photosynthesis?
Answer:
- They follow CAM (Crassulacean Acid Metabolism) pathway.
- CO₂ is taken in at night and stored as malic acid, which is used for photosynthesis during the day when stomata remain closed to conserve water.
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