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Class 10 Science: Life Processes, 8 practice questions with answers

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These are 8 practice questions on NCERT Class 10 Science Chapter 5, Life Processes, each with a short answer and the textbook page it comes from. They cover photosynthesis, the first step of respiration, the heart and blood pressure, and the kidney. Try each one before you read the answer.

These questions are our own, drafted with AI help. Every number was re-computed by a test script and every statement was checked against the chapter, but no practising teacher has reviewed them yet. If you find a mistake, please tell us.

Nutrition and respiration

Question 1. Where in a leaf cell does photosynthesis take place? (In the cell wall; in the chloroplasts, which contain chlorophyll; or in the nucleus.)

Answer: in the chloroplasts, which contain chlorophyll. In a cross-section of a leaf, some cells contain green dots; these are cell organelles called chloroplasts, which contain chlorophyll. (Page 82.)

Question 2. Glucose, a six-carbon molecule, is broken down into pyruvate, a three-carbon molecule. How many pyruvate molecules come from one glucose molecule?

Answer: 2. Six carbon atoms make two groups of three: 6 ÷ 3 = 2 pyruvate molecules. The textbook says the first step of breaking down glucose is into a three-carbon molecule called pyruvate, and that this takes place in the cytoplasm. (Page 87.)

Transport

Question 3. In which blood vessels is the blood pressure much greater? (Veins; neither, it is the same in both; or arteries.)

Answer: arteries. The force that blood exerts against the wall of a vessel is called blood pressure, and this pressure is much greater in arteries than in veins. (Page 93.)

Question 4. Assertion (A): Birds and mammals keep oxygenated and deoxygenated blood separate in the heart. Reason (R): They have high energy needs, using energy all the time to keep their body temperature steady. Choose the correct option: both true and R explains A; both true but R does not explain A; A true and R false; or A false and R true.

Answer: A and R are both true, and R explains A. Separating the right and left sides of the heart keeps oxygenated and deoxygenated blood from mixing, which allows a highly efficient supply of oxygen. This is useful in animals with high energy needs, such as birds and mammals, which constantly use energy to maintain their body temperature. (Page 92.)

Question 5. Why does the heart have different chambers?

Answer: Because both oxygen and carbon dioxide have to be carried by the blood, the heart has different chambers to prevent the oxygen-rich blood from mixing with the blood that contains carbon dioxide. (Page 92.)

Excretion

Question 6. The kidneys of a healthy adult make about 180 L of filtrate a day. About how many litres is that per hour?

Answer: 7.5 L an hour. A day has 24 hours: 180 ÷ 24 = 7.5 litres of filtrate every hour, almost all of it reabsorbed. (The textbook gives the initial filtrate as about 180 L daily and the amount actually excreted as only a litre or two a day, page 97.)

Question 7. What are the filtration units of the kidney called?

Answer: nephrons. Each kidney has large numbers of these filtration units packed close together; a cluster of capillaries is associated with the cup-shaped end of a coiled tube, Bowman's capsule, which collects the filtrate. (Page 97.)

Question 8. The kidneys of a healthy adult form about 180 L of filtrate a day, and about 1.5 L of it leaves the body as urine. (a) How much filtrate is reabsorbed each day? (b) What percentage is that, to one decimal place? (c) How much filtrate is made each hour? (d) How many millilitres of urine are made each hour?

Answer: (a) 180 − 1.5 = 178.5 L. (b) 178.5 ÷ 180 × 100 ≈ 99.2%. (c) 180 ÷ 24 = 7.5 L an hour. (d) 1.5 L = 1,500 mL, and 1,500 ÷ 24 = 62.5 mL an hour. Almost all the filtrate is taken back. (The textbook says only a litre or two is excreted daily, page 97; the 1.5 L is an example value of ours.)

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Sources

All opened and read on 21 October 2026. Page numbers are the printed page numbers of the textbook.

The definitions and facts are from the textbook pages above. The questions, worked answers and checks are our own, and every number was re-computed by script. This guide is general information; follow your teacher and the textbook.