TEACHGYAN.COM | CLASS X | PREPARATORY EXAMINATION – I

SCIENCE (086) – Question Paper

Academic Session: 2026–27   Time: 3 Hours   Maximum Marks: 80

Student Name: ____________________   Roll No.: __________

General Instructions

1. This paper contains 39 questions in three sections: A—Biology (30 marks), B—Chemistry (25 marks) and C—Physics (25 marks).
2. All questions are compulsory. Internal choices are provided in selected questions; attempt only one alternative.
3. Read each question carefully. Draw neat, labelled diagrams wherever required.
4. Use of a calculator is not permitted. Show working in numerical questions.
5. Marks are indicated against each question. The paper is an original TeachGyan preparatory paper aligned to the CBSE 2026–27 sample-paper pattern.

Section A – Biology (30 Marks)

Q1. During photosynthesis, which statement best describes the role of carbon dioxide? (1)
A. It is reduced to form carbohydrates.   B. It is oxidised to release oxygen.   C. It acts as a catalyst.   D. It breaks down chlorophyll.

Q2. Which blood vessel carries oxygenated blood from the lungs to the heart? (1)
A. Pulmonary artery   B. Pulmonary vein   C. Vena cava   D. Aorta

Q3. The opening and closing of stomata is primarily controlled by changes in the: (1)
A. xylem vessels   B. guard cells   C. root hairs   D. epidermal cells

Q4. Which of the following is an example of a vegetative propagation method? (1)
A. Spore formation in Rhizopus   B. Budding in Hydra   C. Growing a new plant from a potato tuber   D. Fertilisation in flowering plants

Q5. Which part of the brain is mainly responsible for maintaining posture and balance? (1)
A. Cerebrum   B. Cerebellum   C. Medulla   D. Hypothalamus

Q6. In human beings, the sex of a child is genetically determined by: (1)
A. the chromosome contributed by the mother only   B. the chromosome contributed by the father   C. nutrition of the mother   D. environmental temperature

Q7. Which of the following is a correct food chain? (1)
A. Grass → Deer → Tiger   B. Tiger → Grass → Deer   C. Deer → Grass → Tiger   D. Grass → Tiger → Deer

Q8. Assertion (A): Arteries have thick and elastic walls. Reason (R): Blood in arteries generally flows under high pressure from the heart. (1)
Choose: A. Both A and R are true and R explains A; B. Both true but R does not explain A; C. A true, R false; D. A false, R true.

Q9. Assertion (A): Variations arising during reproduction may help a species survive environmental changes. Reason (R): All variations are necessarily beneficial to an organism. (1)
Choose the same assertion–reason code as Q8.

Q10. State two functions of hydrochloric acid in the stomach. (2)

Q11. Differentiate between reflex action and voluntary action, giving one example of each. (2)

Q12. Why is the use of condoms considered a useful method of contraception? State two reasons. (2)

Q13. Explain how water and minerals are transported from roots to leaves in plants. (3)

Q14. Describe the process of fertilisation in flowering plants and state what happens to the ovule and ovary after fertilisation. (3)

Q15. Case-based question: A student observed that green plants kept in sunlight release a gas. The student collected the gas in an inverted test tube during an experiment with an aquatic plant. (4)
(a) Name the gas released. (1) (b) Which component of sunlight is trapped by chlorophyll? (1) (c) State one test to identify the collected gas. (1) (d) Why should the plant be kept in sunlight? (1)

Q16. (a) Explain double circulation in human beings with the pathway of blood through the heart. (3) (b) Why is separation of oxygenated and deoxygenated blood advantageous in humans? (2)
OR Explain the structure and functioning of a nephron with a labelled description of filtration and selective reabsorption. (5)