Life Processes Class 10 MCQ Set 1 | Nutrition & Photosynthesis | NCERT JKBOSE CBSE

Topic Coverage: Characteristics of living organisms, defining criteria of life, autotrophic nutrition, photosynthesis (light and dark reactions), chlorophyll, stomata, and plant nutrition.

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📌 Quiz: Biology 10th

📚 Subject: Biology

🏫 Class: Class 10

📖 Chapter: Life Process Set A

📝 Questions: 50

📘 Biology 10th

Biology | Life Process Set A

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Q1. Which of the following is the best defining criteria to consider a thing as alive?

A. Growth

B. Reproduction

C. Cellular organization and metabolism

D. Movement

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Q2. A newly discovered organism shows no visible movement but grows in size over time. To confirm if it is truly alive, what should be tested?

A. Ability to reproduce

B. Presence of a nucleus

C. Occurrence of respiration at the cellular level

D. Ability to respond to touch

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Q3. Which life process is defined as the sum total of all chemical reactions occurring inside a living organism?

A. Nutrition

B. Metabolism

C. Excretion

D. Growth

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Q4. Which of the following is NOT a life process in humans?

A. Respiration

B. Transpiration

C. Excretion

D. Nutrition

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Q5. The process by which living organisms obtain and utilize food for growth, maintenance, and energy is called:

A. Digestion

B. Assimilation

C. Nutrition

D. Absorption

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Q6. Organisms that can synthesize their own food using simple inorganic substances are called:

A. Heterotrophs

B. Saprotrophs

C. Autotrophs

D. Parasites

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Q7. Which of the following is an example of autotrophic nutrition?

A. A lion eating a deer

B. A mushroom growing on decaying log

C. A green alga performing photosynthesis

D. A tapeworm living in the human intestine

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Q8. The process of obtaining food by autotrophs is primarily driven by which energy source?

A. Chemical energy from inorganic compounds

B. Solar energy

C. Geothermal energy

D. Kinetic energy from water flow

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Q9. In autotrophic nutrition, the raw materials required for photosynthesis are:

A. Glucose and oxygen

B. Carbon dioxide and water

C. Chlorophyll and sunlight

D. Nitrogen and minerals

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Q10. What actually happens during photosynthesis at the initial step?

A. Glucose is broken down to release energy

B. Carbon dioxide is fixed into glucose

C. Light energy is absorbed by chlorophyll and converted into chemical energy

D. Oxygen is used to oxidize food

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Q11. During the light reaction of photosynthesis, water molecules are split to release:

A. Only oxygen

B. Oxygen, protons, and electrons

C. Only hydrogen

D. Carbon dioxide and energy

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Q12. What actually happens during the dark reaction (Calvin cycle) of photosynthesis?

A. Light is absorbed by chlorophyll

B. Water is split to release oxygen

C. Carbon dioxide is reduced to form glucose

D. ATP is consumed but not produced

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Q13. The first stable product of carbon fixation in C3 plants is:

A. Oxaloacetic acid

B. Glucose

C. 3-phosphoglyceric acid

D. Ribulose bisphosphate

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Q14. During photosynthesis, what happens to the oxygen produced from the splitting of water?

A. It is used in the dark reaction

B. It is combined with hydrogen to form water again

C. It is released into the atmosphere as a byproduct

D. It is stored in the plant as oxygen gas

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Q15. Which part of the plant cell is the actual site where photosynthesis occurs?

A. Nucleus

B. Mitochondria

C. Chloroplast

D. Vacuole

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Q16. What happens to the glucose produced during photosynthesis?

A. It is immediately converted into carbon dioxide

B. It is used only for respiration

C. It is converted into various organic compounds like starch, cellulose, and oils for storage and growth

D. It is stored only as glucose in the vacuole

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Q17. Which of the following statements correctly describes what happens during photolysis of water?

A. Water is formed by combining hydrogen and oxygen

B. Water molecules are broken down using light energy to provide electrons to chlorophyll

C. Water absorbs carbon dioxide to form glucose

D. Water is transported from roots to leaves

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Q18. Why are plants called autotrophs while animals are called heterotrophs?

A. Plants move, animals do not

B. Plants can synthesize their own food, animals cannot

C. Plants respire, animals do not

D. Plants excrete, animals do not

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Q19. What happens to the energy from sunlight after it is absorbed by chlorophyll?

A. It is lost as heat immediately

B. It is converted into electrical energy, then into chemical energy (ATP and NADPH)

C. It is directly stored in glucose

D. It is used to split carbon dioxide

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Q20. During photosynthesis, what happens to carbon dioxide after it enters the leaf through stomata?

A. It directly combines with glucose

B. It diffuses into the chloroplast stroma and is fixed into an organic molecule

C. It is stored in the vacuole

D. It is broken down to release oxygen

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Q21. Which of the following is NOT required for autotrophic nutrition in green plants?

A. Chlorophyll

B. Carbon dioxide

C. Oxygen gas

D. Water

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Q22. What happens to the ATP and NADPH produced in the light reaction?

A. They are stored permanently in the chloroplast

B. They are used in the dark reaction to reduce carbon dioxide into glucose

C. They are broken down to release energy for plant movement

D. They are transported to roots for storage

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Q23. During the process of photosynthesis, what happens to the stomata?

A. They remain closed to prevent water loss

B. They open to allow carbon dioxide to enter and oxygen to exit

C. They absorb sunlight directly

D. They produce chlorophyll

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Q24. What actually happens if a green plant is kept in complete darkness for several days?

A. It will continue photosynthesis using stored energy

B. It will stop photosynthesis, but glucose will still be produced

C. It will stop producing glucose because the light reaction cannot occur, and the plant may eventually die

D. It will convert its chlorophyll into another pigment

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Q25. Which of the following correctly sequences what happens during photosynthesis from start to finish?

A. Glucose formation → light absorption → water splitting → oxygen release

B. Light absorption → water splitting → ATP/NADPH formation → carbon dioxide fixation → glucose formation

C. Carbon dioxide fixation → light absorption → water splitting → glucose formation

D. Water splitting → glucose formation → light absorption → oxygen release

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Q26. During autotrophic nutrition in plants, what happens to the mineral nutrients like nitrogen, magnesium, and phosphorus?

A. They are used directly to make glucose

B. They are not needed at all

C. They are used to make other biomolecules like proteins, chlorophyll, and ATP

D. They are released as waste products

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Q27. What happens to the rate of photosynthesis if the carbon dioxide concentration around a plant is increased significantly?

A. It will stop completely

B. It will increase up to a certain point, then level off

C. It will decrease continuously

D. It will remain unchanged

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Q28. A student places a test tube containing pond water with green algae in bright sunlight. Bubbles start rising from the algae. What is happening?

A. The algae are respiring and releasing carbon dioxide bubbles

B. The algae are photosynthesizing and releasing oxygen bubbles

C. The algae are boiling due to heat

D. The algae are absorbing oxygen and releasing nitrogen bubbles

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Q29. If a leaf is tested with iodine solution after being kept in sunlight, it turns blue-black. What does this indicate about what happened in the leaf?

A. The leaf absorbed iodine from the air

B. Photosynthesis occurred and starch was produced and stored

C. The leaf lost all its chlorophyll

D. The leaf converted starch back into carbon dioxide

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Q30. What actually happens to the electrons that are removed from water during photolysis?

A. They are released into the atmosphere

B. They are passed through an electron transport chain to ultimately reduce NADP+ to NADPH

C. They combine with oxygen to form water again

D. They are used to split carbon dioxide

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Q31. What is the first event that happens during photosynthesis when sunlight falls on a leaf?

A. Carbon dioxide is reduced to glucose

B. Light energy is absorbed by chlorophyll

C. Water molecules are split into hydrogen and oxygen

D. Stomata open automatically

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Q32. Which pigment present in green plants is primarily responsible for the absorption of light energy during photosynthesis?

A. Carotene

B. Xanthophyll

C. Chlorophyll

D. Anthocyanin

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Q33. What happens immediately after chlorophyll absorbs light energy during photosynthesis?

A. Carbon dioxide is fixed into carbohydrates

B. The energy is used to split water molecules

C. The energy is converted into chemical energy and electrons become excited

D. Stomata close to prevent water loss

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Q34. During the conversion of light energy to chemical energy, which two energy-rich molecules are produced?

A. Glucose and oxygen

B. ATP and NADPH

C. Carbon dioxide and water

D. Chlorophyll and carotene

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Q35. What is the fate of the oxygen produced during the splitting of water molecules in photosynthesis?

A. It is used to break down glucose

B. It is combined with hydrogen to form water again

C. It is released into the atmosphere through stomata

D. It is stored in the chloroplast for later use

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Q36. What happens to the hydrogen produced from the splitting of water molecules?

A. It is released as hydrogen gas into the atmosphere

B. It is used to reduce carbon dioxide into carbohydrates

C. It combines with oxygen to make water inside the leaf

D. It is stored in the vacuole of the plant cell

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Q37. What is the reduction of carbon dioxide to carbohydrates?

A. The process of adding oxygen to carbon dioxide

B. The process of removing hydrogen from carbon dioxide

C. The process of adding hydrogen to carbon dioxide to form glucose

D. The process of breaking down glucose into carbon dioxide

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Q38. Where does the reduction of carbon dioxide to carbohydrates take place inside a plant cell?

A. In the thylakoid membrane of the chloroplast

B. In the stroma of the chloroplast

C. In the nucleus of the cell

D. In the mitochondria

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Q39. Which enzyme is responsible for fixing carbon dioxide during its reduction to carbohydrates?

A. Pepsin

B. Trypsin

C. RuBisCO

D. Amylase

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Q40. What is the first stable product formed when carbon dioxide is reduced to carbohydrates in C3 plants?

A. Glucose

B. Starch

C. 3-phosphoglyceric acid

D. Oxaloacetic acid

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Q41. During the reduction of carbon dioxide to carbohydrates, what is the role of ATP?

A. ATP provides oxygen for the reaction

B. ATP provides the energy needed to convert PGA into glucose

C. ATP splits water molecules

D. ATP absorbs light energy

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Q42. During the reduction of carbon dioxide to carbohydrates, what is the role of NADPH?

A. NADPH absorbs sunlight

B. NADPH provides the hydrogen atoms to reduce carbon dioxide

C. NADPH splits water molecules

D. NADPH closes the stomata

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Q43. Which of the following correctly represents the overall chemical equation for photosynthesis?

A. 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

B. C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O

C. 6CO₂ + 6O₂ → C₆H₁₂O₆ + 6H₂O

D. C₆H₁₂O₆ + 6H₂O → 6CO₂ + 6H₂O

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Q44. What are stomata?

A. Green pigments present in leaves

B. Tiny pores present on the surface of leaves

C. Roots that absorb water

D. Cells that perform photosynthesis

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Q45. What is the function of open stomatal pores during photosynthesis?

A. To prevent water loss from the leaf

B. To allow carbon dioxide to enter the leaf for reduction and oxygen to exit

C. To absorb light energy for chlorophyll

D. To transport glucose to other parts of the plant

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Q46. Which cells are responsible for the opening and closing of stomatal pores?

A. Epidermal cells

B. Mesophyll cells

C. Guard cells

D. Xylem cells

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Q47. What happens to the guard cells when water enters them?

A. They become flaccid and the stomatal pore closes

B. They become turgid (swollen) and the stomatal pore opens

C. They divide to form more guard cells

D. They lose chlorophyll and become colorless

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Q48. What happens to the guard cells when they lose water?

A. They become turgid and the stomatal pore opens

B. They become flaccid (shriveled) and the stomatal pore closes

C. They become longer and wider

D. They start performing photosynthesis rapidly

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Q49. Why do stomata generally remain open during the daytime?

A. Because the plant wants to lose as much water as possible

B. Because light triggers the guard cells to take up water and open, allowing CO₂ for photosynthesis

C. Because the plant wants to store oxygen inside the leaves

D. Because the temperature is lower during the day

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Q50. Why do stomata often close at night?

A. Because the plant does not need carbon dioxide at night since no light means no reduction of CO₂ to carbohydrates

B. Because the plant wants to absorb more oxygen

C. Because the guard cells lose chlorophyll at night

D. Because the roots stop supplying water at night

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