Class 10 Science · Chapter 5

Life Processes

431 Class 10 Science questions on Life Processes from the NCERT textbook, NCERT Exemplar and CBSE board papers 2018–2026, each with its answer and a step-by-step solution.

CBSE Class 10 Science previous year papers, with answers →

Questions · page 16 of 22

1. Q301 CBSE 2023
   Sphincter ​muscles ​are ​present ​at the exit ​of ​:

   1. (a)Stomach and small intestine
   2. (b)Stomach and anus
   3. (c)Small intestine and large intestine
   4. (d)Oesophagus and stomach
   Show answer

   (b) Stomach and anus

   Step-by-step solution →
2. Q302 CBSE 2023
   Observe the ​following diagram ​and identify ​the process and ​its ​significance ​from ​the ​following options :

   1. (a)Evaporation : maintains water contents in leaf cells.
   2. (b)Transpiration : creates a suction force which pulls water inside the plant.
   3. (c)Excretion : helps in excreting out waste water from the plant.
   4. (d)Translocation : helps in transporting materials from one cell to another.
   Show answer

   (b) Transpiration : creates a suction force which pulls water inside the plant.

   Step-by-step solution →
3. Q303 CBSE 2023
   The process ​in ​which loss of ​water in ​the ​form of vapours from the aerial parts of plants ​takes place is $X$, which helps in $Y$. ​Here $X$ and $Y$ respectively are ​:

   1. (a)transpiration and photosynthesis.
   2. (b)transpiration and temperature regulation.
   3. (c)translocation and movement of soluble products of photosynthesis in phloem.
   4. (d)translocation and absorption of water and minerals from soil by roots.
   Show answer

   (b) transpiration and temperature regulation.

   Step-by-step solution →
4. Q304 CBSE 2023
   The ​inner ​lining of stomach is ​protected from hydrochloric ​acid ​by ​:

   1. (a)Bile
   2. (b)Mucus
   3. (c)Pepsin
   4. (d)Saliva
   Show answer

   (b) Mucus

   Step-by-step solution →
5. Q305 CBSE 2023
   Which one of the following molecules is ​produced ​initially when glucose ​breaks down in ​the cytoplasm of a cell in aerobic ​as ​well ​as anaerobic respiration ?

   1. (a)Lactic acid
   2. (b)Ethanol
   3. (c)Carbon dioxide
   4. (d)Pyruvate
   Show answer

   (d) Pyruvate

   Step-by-step solution →
6. Q306 CBSE 2023
   Consider ​the ​following statements about small ​intestine ​and ​select ​the one ​which is NOT ​correct :

   1. (a)The length of the small intestine in animals differs as it depends on the type of food they eat.
   2. (b)The small intestine is the site of complete digestion of food.
   3. (c)The small intestine receives secretions from liver and pancreas.
   4. (d)The villi of the small intestine absorb water from the unabsorbed food before it gets removed from the body via the anus.
   Show answer

   (d) The villi of the small intestine absorb water from the unabsorbed food before it gets removed from the body via the anus.

   Step-by-step solution →
7. Q307 CBSE 2023
   In ​the following diagram, identify the ​cells through ​which massive amounts ​of ​gaseous exchange takes ​place for ​photosynthesis :

   1. (a)I
   2. (b)IV
   3. (c)III
   4. (d)II
   Show answer

   (b) IV

   Step-by-step solution →
8. Q308 CBSE 2023
   Opening ​and ​closing ​of ​stomata ​is due to ​:

   1. (a)High pressure of gases inside the cells.
   2. (b)Movement of water in and out of the guard cells.
   3. (c)Stimulus of light in the guard cells.
   4. (d)Diffusion of ${\text{CO}}_2$ in and out of the guard cells.
   Show answer

   (b) Movement of water in and out of the guard cells.

   Step-by-step solution →
9. Q309 CBSE 2023
   As ​compared ​to ​terrestrial organisms, the rate ​of ​breathing in ​aquatic organisms ​is ​:

   1. (a)faster because they need more oxygen for their survival.
   2. (b)faster because the amount of dissolved oxygen in water is fairly low.
   3. (c)slower because the amount of dissolved oxygen in water is fairly low.
   4. (d)slower because the capacity of water of dissolving atmospheric air is limited.
   Show answer

   (b) faster because the amount of dissolved oxygen in water is fairly low.

   Step-by-step solution →
10. Q310 CBSE 2023
    During deficiency of oxygen in the ​tissues of human beings, pyruvate ​is ​converted into ​lactic ​acid ​in ​:

    1. (a)cytoplasm
    2. (b)golgi body
    3. (c)mitochondria
    4. (d)chloroplast
    Show answer

    (a) cytoplasm

    Step-by-step solution →
11. Q311 CBSE 2023
    Select ​the ​correct ​statement from ​the ​following :

    1. (a)Trypsin digests proteins, whereas lipase digests carbohydrates.
    2. (b)Trypsin digests carbohydrates, whereas lipase digests proteins.
    3. (c)Trypsin digests emulsified fats, whereas lipase digests proteins.
    4. (d)Trypsin digests proteins, whereas lipase digests emulsified fats.
    Show answer

    (d) Trypsin digests proteins, whereas lipase digests emulsified fats.

    Step-by-step solution →
12. Q312 CBSE 2023
    As ​compared ​to daytime, the amount ​of ​carbon ​dioxide ​released by the plants during night ​is ​more because :

    1. (a)It is not produced during daytime.
    2. (b)It is stored in the leaves of plants during daytime.
    3. (c)Major amount of carbon dioxide produced is used up for photosynthesis during daytime.
    4. (d)Plants do not respire during daytime.
    Show answer

    (c) Major amount of carbon dioxide produced is used up for photosynthesis during daytime.

    Step-by-step solution →
13. Q313 CBSE 2023
    Water in ​the root ​enters due ​to ​:

    1. (a)the function of the root to absorb water.
    2. (b)difference in the concentration of ions between the root and the soil.
    3. (c)excess water present in the soil.
    4. (d)diffusion of water in the roots.
    Show answer

    (b) difference in the concentration of ions between the root and the soil.

    Step-by-step solution →
14. Q314 CBSE 2023
    During ​vigorous exercise, the occurrence of ​cramps in ​the ​outer muscles of an athlete is due to the ​conversion of pyruvate to ​:

    1. (a)Glucose
    2. (b)Ethanol
    3. (c)Lactic acid
    4. (d)Lactose
    Show answer

    (c) Lactic acid

    Step-by-step solution →
15. Q315 CBSE 2023
    One of the ​events that ​does not occur during ​photosynthesis is ​:

    1. (a)Chlorophyll absorbs solar energy.
    2. (b)Carbon dioxide is released during the process.
    3. (c)Oxygen is released during the process.
    4. (d)Carbon dioxide is absorbed during the process.
    Show answer

    (b) Carbon dioxide is released during the process.

    Step-by-step solution →
16. Q316 CBSE 2023
    Two ​statements are given — one labelled ​as ​Assertion (A) and the ​other ​labelled as Reason (R). Select the ​correct answer to this question from the codes (a), (b), ​(c) and (d) as given below.

    Assertion (A): ATP is the energy currency for most of the cellular processes.

    Reason (R): Endothermic processes in the cell use ATP to carry out reactions.

    1. (a)Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of the Assertion (A).
    2. (b)Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
    3. (c)Assertion (A) is true, but Reason (R) is false.
    4. (d)Assertion (A) is false, but Reason (R) is true.
    Show answer

    (a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of the Assertion (A).

    Step-by-step solution →
17. Q317 CBSE 2023
    These ​consist of two statements – ​Assertion (A) ​and Reason (R). ​Answer this question selecting the appropriate option ​given ​below :

    Assertion (A): The anaerobic respiration which takes place in yeast, has one of the end products as an acid.

    Reason (R): During anaerobic respiration, there is incomplete breakdown of glucose.

    1. (a)Both (A) and (R) are true and (R) is the correct explanation of (A).
    2. (b)Both (A) and (R) are true, but (R) is not the correct explanation of (A).
    3. (c)(A) is true, but (R) is false.
    4. (d)(A) is false, but (R) is true.
    Show answer

    (d) (A) is false, but (R) is true.

    Step-by-step solution →
18. Q318 CBSE 2023
    These ​consist ​of two ​statements – ​Assertion (A) ​and Reason (R). Answer this question ​selecting the appropriate option ​given below :

    Assertion (A): Blood clotting prevents excessive loss of blood.

    Reason (R): Blood clotting is due to blood plasma and white blood cells present in the blood.

    1. (a)Both (A) and (R) are true and (R) is the correct explanation of (A).
    2. (b)Both (A) and (R) are true, but (R) is not the correct explanation of (A).
    3. (c)(A) is true, but (R) is false.
    4. (d)(A) is false, but (R) is true.
    Show answer

    (c) (A) is true, but (R) is false.

    Step-by-step solution →
19. Q319 CBSE 2023
    These consist of two ​statements ​– Assertion (A) ​and Reason (R). ​Answer this ​question selecting the ​appropriate ​option ​given below.

    Assertion (A): The inner walls of the small intestine have finger like projections called villi which are rich in blood.

    Reason (R): These villi have a large surface area to help the small intestine in completing the digestion of food.

    1. (a)Both (A) and (R) are true and (R) is the correct explanation of (A).
    2. (b)Both (A) and (R) are true but (R) is not the correct explanation of (A).
    3. (c)(A) is true but (R) is false.
    4. (d)(A) is false but (R) is true.
    Show answer

    (c) (A) is true but (R) is false.

    Step-by-step solution →
20. Q320 CBSE 2023
    Two ​statements are ​given — ​one ​labelled ​as Assertion (A) and the other labelled as Reason ​(R). ​Select the correct ​answer to this question from the codes (a), (b), (c) and (d) as given below :

    Assertion (A): The walls of atria are thicker than those of the ventricles.

    Reason (R): Ventricles have to pump blood into various organs at high pressure.

    1. (a)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
    2. (b)Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
    3. (c)Assertion (A) is true, but Reason (R) is false.
    4. (d)Assertion (A) is false, but Reason (R) is true.
    Show answer

    (d) Assertion (A) is false, but Reason (R) is true.

    Step-by-step solution →