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 7 of 22

1. Q121 CBSE 2026
   Name ​the enzyme that acts ​on the ​protein-rich diet ​inside our ​stomach ​:

   1. (a)Pepsin
   2. (b)Amylase
   3. (c)Trypsin
   4. (d)Lipase
   Show answer

   (a) Pepsin

   Step-by-step solution →
2. Q122 CBSE 2026
   Select ​the ​correct option that ​shows ​the path of flow ​of only the ​deoxygenated blood through the human ​circulatory system.

   1. (a)Body $⟶$ left atrium $⟶$ left ventricle $⟶$ lungs $⟶$ right atrium $⟶$ right ventricle $⟶$ body.
   2. (b)Right atrium $⟶$ right ventricle $⟶$ lungs $⟶$ left atrium $⟶$ left ventricle $⟶$ body
   3. (c)Body $⟶$ left atrium $⟶$ left ventricle $⟶$ lungs
   4. (d)Body $⟶$ right atrium $⟶$ right ventricle $⟶$ lungs
   Show answer

   (d) Body $⟶$ right atrium $⟶$ right ventricle $⟶$ lungs

   Step-by-step solution →
3. Q123 CBSE 2026
   The inner lining of the small intestine has numerous finger-like ​projections called villi. Choose ​the ​correct ​option indicating the ​function of villi.

   1. (a)It increases surface area for digestion of food.
   2. (b)It decreases surface area for absorption of food.
   3. (c)It secretes enzymes required for digestion of food.
   4. (d)It increases surface area for absorption of food.
   Show answer

   (d) It increases surface area for absorption of food.

   Step-by-step solution →
4. Q124 CBSE 2026
   Observe ​the figure ​given below ​and ​identify ​the incorrect step for the activity ​set-up :

   1. (a)Both plants are kept in the dark room for three days before placing them in separate glass jars.
   2. (b)Both plants are covered with separate wooden bell-jars.
   3. (c)Use vaseline to seal the bottom of the jars with the glass plates.
   4. (d)Both potted plants were kept in sunlight for a few hours before the iodine test for the presence of starch.
   Show answer

   (b) Both plants are covered with separate wooden bell-jars.

   Step-by-step solution →
5. Q125 CBSE 2026
   Which ​of ​the following is ​not ​a ​function ​of ​transpiration ?

   1. (a)It helps in regulation of temperature.
   2. (b)It helps in upward movement of water.
   3. (c)It transports food to different parts of the plant body.
   4. (d)It helps in movement of minerals from the roots to the leaves.
   Show answer

   (c) It transports food to different parts of the plant body.

   Step-by-step solution →
6. Q126 CBSE 2026
   Which ​of the ​following ​groups consists entirely ​of ​substances ​that ​are broken down by an enzyme, lipase ?

   1. (a)Carbohydrates, proteins and vitamins
   2. (b)Fats, oils and ghee
   3. (c)Minerals, starch and vitamins
   4. (d)Proteins, sugars and esters
   Show answer

   (b) Fats, oils and ghee

   Step-by-step solution →
7. Q127 CBSE 2026
   Choose ​the option that indicates the common structure ​between the basic ​filtration unit of kidneys ​and in ​the walls ​of alveoli of lungs.

   1. (a)Thin-walled veins poorly supplied with blood.
   2. (b)Thick-walled arteries richly supplied with blood.
   3. (c)A cluster of thin-walled capillaries richly supplied with blood.
   4. (d)Thick-walled capillaries poorly supplied with blood.
   Show answer

   (c) A cluster of thin-walled capillaries richly supplied with blood.

   Step-by-step solution →
8. Q128 CBSE 2026
   Choose the equation ​of ​reaction that ​correctly represents ​anaerobic respiration ​in muscles ​:

   1. (a)$\text{Glucose}\to \text{Pyruvate}\underset{{\text{of O}}_2}{\overset{\text{Absence}}{\to }}\text{Ethanol}+{\text{CO}}_2+\text{Energy}$
   2. (b)$\text{Glucose}\stackrel{{\text{O}}_2}{\to }\text{Pyruvate}\stackrel{{\text{O}}_2}{\to }\text{Energy}$
   3. (c)$\text{Glucose}\stackrel{{\text{O}}_2}{\to }\text{Pyruvate}\underset{\text{oxygen}}{\overset{\text{Lack of}}{\to }}\text{Ethanol}+\text{Energy}$
   4. (d)$\text{Glucose}\to \text{Pyruvate}\underset{\text{oxygen}}{\overset{\text{Lack of}}{\to }}\text{Lactic acid}+\text{Energy}$
   Show answer

   (d) $\text{Glucose}\to \text{Pyruvate}\underset{\text{oxygen}}{\overset{\text{Lack of}}{\to }}\text{Lactic acid}+\text{Energy}$

   Step-by-step solution →
9. Q129 CBSE 2026
   ‘The lymph ​is colourless tissue ​fluid.’ This ​indicates that it lacks ____(i)____ cells and hence ​cannot carry ____(ii)____ . From the ​following options, choose the one ​that correctly ​identifies

   1. (i)and
   2. (ii).

   1. (a)(i) – Platelets ; (ii) – excess fluid
   2. (b)(i) – Red blood ; (ii) – oxygen
   3. (c)(i) – Red blood ; (ii) – fats
   4. (d)(i) – White blood ; (ii) – salts
   Show answer

   (b) (i) – Red blood ; (ii) – oxygen

   Step-by-step solution →
10. Q130 CBSE 2026
    Given below ​a set ​of statements regarding ​blood ​circulation in humans. Identify ​the ​correct statement.

    1. (a)Oxygenated blood from lungs comes to the right auricle through pulmonary veins.
    2. (b)Vena cavas take oxygenated blood from body parts to right auricle.
    3. (c)Pulmonary artery takes oxygenated blood from heart to lungs.
    4. (d)Aorta takes oxygenated blood from heart to body parts.
    Show answer

    (d) Aorta takes oxygenated blood from heart to body parts.

    Step-by-step solution →
11. Q131 CBSE 2026
    Four ​chambered ​heart ​is ​a characteristic ​of ​:

    1. (a)Fishes
    2. (b)Amphibians
    3. (c)Reptiles
    4. (d)Mammals
    Show answer

    (d) Mammals

    Step-by-step solution →
12. Q132 CBSE 2026
    The carbohydrates, which are not used ​immediately in plants, ​are stored in the form ​of ‘a’, ​which serves as an ​internal energy reserve. ​What does ​‘a’ stand for ​?

    1. (a)Starch
    2. (b)Sugar
    3. (c)Fat
    4. (d)Protein
    Show answer

    (a) Starch

    Step-by-step solution →
13. Q133 CBSE 2026
    If the stomatal pore is open, it indicates ​which ​situation ​from ​the ​following ​?

    1. (a)The guard cells have shrunk.
    2. (b)The water comes out of the guard cells.
    3. (c)Large amount of water is lost through stomata.
    4. (d)The guard cells have swelled due to inflow of water.
    Show answer

    (d) The guard cells have swelled due to inflow of water.

    Step-by-step solution →
14. Q134 CBSE 2026
    Translocation is the process ​in ​which ​plants ​deliver :

    1. (a)Minerals from leaves to other parts of the plant.
    2. (b)Plant growth hormones from leaves to other parts of the plant.
    3. (c)Water and inorganic substances from leaves to other parts of the plant.
    4. (d)Organic substances from leaves to the other parts of the plant.
    Show answer

    (d) Organic substances from leaves to the other parts of the plant.

    Step-by-step solution →
15. Q135 CBSE 2026
    Pancreas secretes ​pancreatic juice which ​contain certain ​enzyme ​that ​helps in digestion of food. Choose the ​correct option from the following :

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

    (b) Trypsin digests proteins and lipase digests emulsified fats.

    Step-by-step solution →
16. Q136 CBSE 2026
    The following events occur during the process of photosynthesis. ​Choose the ​option that ​indicates the correct events.

    1. (i)Oxidation of ​carbon dioxide to carbohydrates
    2. (ii)Conversion of ​light energy into chemical ​energy
    3. (iii)Absorption of light energy by chlorophyll
    4. (iv)Conversion of ​hydrogen and ​oxygen into water Options :

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

    (b) (ii) and (iii)

    Step-by-step solution →
17. Q137 CBSE 2026
    Select ​the option ​that represents the ​correct ​balanced ​equation for the process ​of ​photosynthesis :

    1. (a)${\text{CO}}_2+{\text{O}}_2+{\text{H}}_2\text{O}\stackrel{\text{Chlorophyll}}{\to }{\text{C}}_6{\text{H}}_{12}{\text{O}}_6+{\text{H}}_2\text{O}$
    2. (b)$6{\text{CO}}_2+6{\text{H}}_2\text{O}\underset{\text{Sunlight}}{\overset{\text{Chlorophyll}}{\to }}{\text{C}}_6{\text{H}}_{12}{\text{O}}_6+{\text{O}}_2$
    3. (c)${\text{CO}}_2+{\text{H}}_2\text{O}\stackrel{\text{Sunlight}}{\to }{\text{C}}_6{\text{H}}_{12}{\text{O}}_6$
    4. (d)$6{\text{CO}}_2+12{\text{H}}_2\text{O}\underset{\text{Sunlight}}{\overset{\text{Chlorophyll}}{\to }}{\text{C}}_6{\text{H}}_{12}{\text{O}}_6+6{\text{O}}_2+6{\text{H}}_2\text{O}$
    Show answer

    (d) $6{\text{CO}}_2+12{\text{H}}_2\text{O}\underset{\text{Sunlight}}{\overset{\text{Chlorophyll}}{\to }}{\text{C}}_6{\text{H}}_{12}{\text{O}}_6+6{\text{O}}_2+6{\text{H}}_2\text{O}$

    Step-by-step solution →
18. Q138 CBSE 2026
    The capillary net-like (web-like) ​structure in the ​kidney ​associated with a ​cup-shaped ​structure ​is called :

    1. (a)Nephron
    2. (b)Collecting duct
    3. (c)Glomerulus
    4. (d)Bowman's capsule
    Show answer

    (c) Glomerulus

    Step-by-step solution →
19. Q139 CBSE 2026
    In which of the following structures ​of a cell does the ​process of breakdown ​of pyruvate using ​oxygen to form ​carbon ​dioxide, water and energy ​take place ?

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

    (b) Mitochondria

    Step-by-step solution →
20. Q140 CBSE 2026
    Study the given diagram of the heart, with blood vessels marked ‘1’ and ‘2’. From the following statements, ​establish the ​relationship between heart and /or the two blood ​vessels :

    1. (i)Blood vessel 1 - It ​carries carbon dioxide rich blood to the lungs.
    2. (ii)Blood vessel 2 - It carries oxygen ​rich blood from the lungs.
    3. (iii)Blood vessel 2 - Left atrium relaxes as it receives blood from this blood vessel.
    4. (iv)Blood vessel 1 - Right atrium has thick wall as it has to pump blood to ​this vessel. The ​option with correct statements is :

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

    (d) (i), (ii) and (iii)

    Step-by-step solution →