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 11 of 22

1. Q201 CBSE 2025
   Listed below are the steps of ​nutrition in Amoeba. ​Select the ​correct sequence of these steps :

   1. (i)Diffusion of simple nutrients into cytoplasm
   2. (ii)Food ​vacuole formation
   3. (iii)Formation of finger like temporary extensions of cell surface
   4. (iv)Complex substances broken to simpler ones
   5. (v)​Undigested ​material thrown out of the ​cell surface

   1. (a)(iv), (i), (ii), (iii), (v)
   2. (b)(iii), (ii), (iv), (i), (v)
   3. (c)(ii), (i), (iv), (v), (iii)
   4. (d)(iii), (iv), (i), (ii), (v)
   Show answer

   (b) (iii), (ii), (iv), (i), (v)

   Step-by-step solution →
2. Q202 CBSE 2025
   The ​substances ​that ​are selectively reabsorbed from the tubular part of the nephron as the urine ​flow through ​it ​are

   1. (a)amino acids and salts only
   2. (b)amino acids, salts, glucose and water
   3. (c)salts and glucose only
   4. (d)water, amino acids and glucose
   Show answer

   (b) amino acids, salts, glucose and water

   Step-by-step solution →
3. Q203 CBSE 2025
   In the human ​alimentary canal, when the process ​of digestion ​is completed, the

   1. (i)carbohydrates,
   2. (ii)fats, and
   3. (iii)​proteins get ​converted ​respectively into :

   1. (a)(i) glucose, (ii) fatty acids and (iii) amino acids
   2. (b)(i) glucose, (ii) fatty acids and glycerol and (iii) amino acids
   3. (c)(i) fatty acids and glycerol, (ii) amino acids and (iii) glucose
   4. (d)(i) amino acids, (ii) fatty acids and glycerol and (iii) sugars
   Show answer

   (b) (i) glucose, (ii) fatty acids and glycerol and (iii) amino acids

   Step-by-step solution →
4. Q204 CBSE 2025
   The ​gastric glands present ​in the ​wall of ​the ​stomach ​release ​:

   1. (a)Mucus and Trypsin
   2. (b)Pepsin and Trypsin
   3. (c)Mucus and Pepsin
   4. (d)Pepsin and Salivary amylase
   Show answer

   (c) Mucus and Pepsin

   Step-by-step solution →
5. Q205 CBSE 2025
   Temporary finger-like extensions on ​the cell surface ​to ​take in ​food ​is ​formed in :

   1. (a)Paramoecium
   2. (b)Amoeba
   3. (c)Leishmania
   4. (d)Rhizopus
   Show answer

   (b) Amoeba

   Step-by-step solution →
6. Q206 CBSE 2025
   Parasitic ​mode ​of nutrition ​is ​observed ​in :

   1. (a)Bryophyllum
   2. (b)Hibiscus
   3. (c)Cuscuta
   4. (d)Helianthus
   Show answer

   (c) Cuscuta

   Step-by-step solution →
7. Q207 CBSE 2025
   The basic filtration unit ​of ​the excretory ​system in ​human ​beings is ​:

   1. (a)Nephron
   2. (b)Urethra
   3. (c)Neuron
   4. (d)Urinary bladder
   Show answer

   (a) Nephron

   Step-by-step solution →
8. Q208 CBSE 2025
   Which one ​of the ​following ​is not an ​excretory ​product in plants ?

   1. (a)${\text{CO}}_2$
   2. (b)Starch
   3. (c)Resins and gums
   4. (d)Dead cells
   Show answer

   (b) Starch

   Step-by-step solution →
9. Q209 CBSE 2025
   The breakdown of glucose ​has taken ​the following pathway : $$\text{Glucose}\stackrel{(a)}{\to }\text{Pyruvate}+\text{Energy}\stackrel{(b)}{\to }\text{Lactic acid}+\text{Energy}$$ The sites ‘a’ and ‘b’ ​respectively are :

   1. (a)Mitochondria and Oxygen deficient muscle cells
   2. (b)Cytoplasm and Oxygen rich muscle cells
   3. (c)Cytoplasm and Yeast cells
   4. (d)Cytoplasm and Oxygen deficient muscle cells
   Show answer

   (d) Cytoplasm and Oxygen deficient muscle cells

   Step-by-step solution →
10. Q210 CBSE 2025
    In ​aerobic respiration, the steps are : ​breakdown of glucose ​to pyruvate and its further conversion ​to ​carbon ​dioxide. Both processes respectively ​occur ​in –

    1. (a)Vacuole and Cytoplasm
    2. (b)Chloroplast and Mitochondria
    3. (c)Mitochondria and Cytoplasm
    4. (d)Cytoplasm and Mitochondria
    Show answer

    (d) Cytoplasm and Mitochondria

    Step-by-step solution →
11. Q211 CBSE 2025
    In ​human ​alimentary ​canal, the digestive juice secreted ​by the ​gastric glands ​are

    1. (a)Bile, Trypsin, Pepsin
    2. (b)Hydrochloric acid, Pepsin, Mucus
    3. (c)Lipase, Bile, Mucus
    4. (d)Salivary amylase, Pepsin, Bile
    Show answer

    (b) Hydrochloric acid, Pepsin, Mucus

    Step-by-step solution →
12. Q212 CBSE 2025
    Two statements ​are given — one labelled ​Assertion (A) ​and the ​other labelled Reason (R). Select the correct answer to this question ​from the codes (a), (b), (c) ​and (d) given ​below.

    Assertion (A): In large animals, oxygen can reach different parts of the animal’s body easily.

    Reason (R): Respiratory pigments take up oxygen from the air and carry it to body tissues.

    1. (a)Both, Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
    2. (b)Both, Assertion (A) and Reason (R) are true, and Reason (R) is not the correct explanation of 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 Assertion (A).

    Step-by-step solution →
13. Q213 CBSE 2025
    Two statements are given below — 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): Transpirational pull helps in the absorption and upward movement of water and dissolved minerals in plants.

    Reason (R): The effect of root pressure in transport of water is more significant at night.

    1. (a)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
    2. (b)Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of 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

    (b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).

    Step-by-step solution →
14. Q214 CBSE 2025
    Two statements ​are given below – 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) given ​below.

    Assertion (A): Xylem tissue moves water and minerals obtained from the soil by the roots.

    Reason (R): Xylem tissue is found only in the roots of a plant.

    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 and 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

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

    Step-by-step solution →
15. Q215 CBSE 2025
    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 rate of breathing in aquatic organisms is faster than that in terrestrial organisms.

    Reason (R): The amount of oxygen dissolved in pond/river water is comparatively higher than the amount of oxygen present in air.

    1. (a)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
    2. (b)Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of 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

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

    Step-by-step solution →
16. Q216 CBSE 2025
    Two ​statements ​are given — one labelled as ​Assertion (A) ​and the other ​labelled as Reason (R). ​Select the correct answer from the codes given ​below.

    Assertion (A): Animals will not get energy if they eat (consume) coal as food.

    Reason (R): Specific enzymes are needed for the breakdown of a particular food.

    1. (a)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
    2. (b)Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of 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 Assertion (A).

    Step-by-step solution →
17. Q217 CBSE 2025
    Photosynthesis takes place in the leaves of ​a ​plant ​and the food ​prepared by the leaves ​reaches other parts of the plant. Name and explain the process ​involved in the ​phenomenon.
    Show answer

    Translocation by the phloem: food loaded into sieve tubes raises the pressure, which pushes the sap to roots, fruits, seeds and buds.

    The process is **translocation**, and it is carried out by the phloem. Sucrose and other soluble products of photosynthesis are loaded from the leaf into the sieve tubes by the companion cells using energy from ATP. The sap inside is then concentrated, so water enters it by osmosis from the xylem and the pressure in the tube rises. That pressure pushes the sap along to parts where the pressure is lower — roots, fruits, seeds and growing buds — where the food is unloaded and used or stored. Because a pressure difference is what drives it, translocation can carry food upwards as well as downwards, unlike the xylem, which moves water and minerals upwards only.

    Step-by-step solution →
18. Q218 CBSE 2025
    State ​the ​main function ​of veins ​in human circulatory system. Why do they not need ​thick walls ?
    Show answer

    Veins carry blood from the organs back to the heart; their walls can be thin because the blood is at low pressure.

    Veins collect blood from the various organs of the body and carry it back to the heart (all except the pulmonary vein carry deoxygenated blood). They do not need thick walls because the blood in them is no longer under high pressure — most of the pressure has been used up in forcing the blood through the narrow capillaries — so instead of thick elastic walls they have wide lumens and valves that keep the slow blood flowing only towards the heart.

    Step-by-step solution →
19. Q219 CBSE 2025
    Give reasons : ​

    1. (a)During a breathing cycle, the lungs always contain ​a residual volume of ​air.
    2. (b)​As compared to oxygen, ​carbon dioxide is mostly ​transported in dissolved ​form in ​our blood.
    Show answer

    Residual air keeps gas exchange going between breaths; carbon dioxide is far more soluble than oxygen, so it travels dissolved in plasma.

    (a) The lungs are never emptied completely because the residual air keeps the alveoli filled, so that there is sufficient time for oxygen to be absorbed by the blood and for carbon dioxide to be released, and gas exchange continues even between two breaths. (b) Carbon dioxide is far more soluble in water, and hence in blood plasma, than oxygen is, so it can simply dissolve in the plasma and be carried in that form; oxygen dissolves poorly, so it has to be carried bound to the respiratory pigment haemoglobin in the red blood cells.

    Step-by-step solution →
20. Q220 CBSE 2025
    “Plants use a variety of ​techniques to get rid ​of waste ​material.” ​Justify this ​statement ​giving ​any four ways.
    Show answer

    Plants have no excretory organ: gases diffuse out, excess water is transpired, and other wastes are stored or shed with leaves.

    A plant has no excretory organ, so it removes different wastes in different ways, which is why the statement is justified. Any four of the following: (i) Gaseous wastes such as oxygen from photosynthesis and carbon dioxide from respiration diffuse out through the stomata of leaves and the lenticels of stems; (ii) Excess water is got rid of by transpiration; (iii) Many wastes are stored in the vacuoles of the cells; (iv) Wastes are stored as resins and gums, particularly in old xylem; (v) Wastes are moved into old leaves, which are then shed; (vi) Some waste products are released into the soil around the roots.

    Step-by-step solution →