Created by Titas Mallick
Biology Teacher • M.Sc. Botany • B.Ed. • CTET (CBSE) • CISCE Examiner
BioNotesBioNotesCreated by Titas Mallick
Biology Teacher • M.Sc. Botany • B.Ed. • CTET (CBSE) • CISCE Examiner
Online
Practice question paper (80 marks, 2 hours) for ICSE Class X Biology, Science Paper 3, 2027 pattern.
Maximum Marks: 80 | Time Allowed: Two Hours
Additional 15 minutes are allowed for reading the question paper only. You must NOT start writing during this time.
This is a practice paper prepared on the ICSE 2027 specimen pattern. Syllabus coverage follows the CISCE ICSE 2027 Biology (Science Paper 3) Class X syllabus.
Choose the correct answers to the questions from the given options. (Do not copy the question, write the correct answer only.)
(i) Plasmolysis occurs when a plant cell is placed in a:
(a) hypotonic solution
(b) isotonic solution
(c) hypertonic solution
(d) pure water
(ii) Assertion (A): Blood in the pulmonary vein is oxygenated.
Reason (R): The pulmonary vein carries blood from the lungs to the left auricle.
(a) (A) is true and (R) is false.
(b) (A) is false and (R) is true.
(c) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(d) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(iii) The plant growth regulator that hastens the ripening of fruits is:
(a) auxin
(b) gibberellin
(c) cytokinin
(d) ethylene
(iv) Erythroblastosis foetalis (haemolytic disease of the newborn) may occur when:
(a) an Rh-positive mother carries an Rh-negative foetus
(b) an Rh-negative mother carries an Rh-positive foetus
(c) both parents are Rh-negative
(d) both parents are Rh-positive
(v) Simple goitre (swelling of the neck) is caused due to deficiency of:
(a) iron
(b) iodine
(c) calcium
(d) sodium
(vi) Which of the following statements are correct?
P – Xylem vessels conduct water from the roots to the leaves.
Q – Transpiration pull is created by the evaporation of water from mesophyll cells.
R – Root pressure alone is sufficient to raise water in the tallest trees.
S – Stomata generally open in the presence of light.
(a) P and Q only
(b) Q and R only
(c) P, Q and S
(d) R and S only
(vii) A human cell in the G₁ phase has 46 chromosomes. After the S phase, the number of chromosomes and chromatids will be respectively:
(a) 46 and 46
(b) 92 and 92
(c) 46 and 92
(d) 92 and 46
(viii) The part of the human ear responsible for maintaining the balance of the body is the:
(a) cochlea
(b) semicircular canals
(c) tympanic membrane
(d) Eustachian tube
(ix) Assertion (A): Arteries have thick, elastic walls.
Reason (R): Arteries carry blood at high pressure.
(a) (A) is true and (R) is false.
(b) (A) is false and (R) is true.
(c) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(d) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(x) Rahul's red blood cells carry both A and B antigens and his plasma has no antibodies. His blood group is:
(a) A
(b) B
(c) O
(d) AB
(xi) The hormone released by the posterior pituitary that regulates the water balance of the body is:
(a) oxytocin
(b) ADH
(c) growth hormone
(d) TSH
(xii) In a dihybrid cross between two pure-breeding plants (RRYY × rryy), the phenotypic ratio in the F₂ generation is:
(a) 9 : 3 : 3 : 1
(b) 3 : 1
(c) 1 : 2 : 1
(d) 1 : 1 : 1 : 1
(xiii) When hot water from a power plant is discharged into a river, the dissolved oxygen content of the water:
(a) decreases
(b) increases
(c) remains the same
(d) first increases, then remains constant
(xiv) The increase in the number of dark-coloured peppered moths in industrial areas is an example of:
(a) Lamarck's theory of use and disuse
(b) Darwin's theory of natural selection
(c) Mendel's law of dominance
(d) inheritance of acquired characters
(xv) In a town, there are 30 births and 10 deaths per 1000 individuals in a year. The growth rate of the population is:
(a) 1%
(b) 2%
(c) 3%
(d) 4%
(i) Give the biological/technical terms for the following: [5]
(a) The loss of sap in liquid form from the cut end of a stem.
(b) The region of the retina where vision is sharpest.
(c) The hormone that prepares the body for an emergency ("fight or flight").
(d) The process of giving birth to a baby.
(e) The stage of mitosis in which the chromosomes line up at the equator of the cell.
(ii) Fill in the blanks by selecting the correct words from the word bank. [5]
Word bank: potassium, endosmosis, exosmosis, turgid, flaccid, open, closed, sodium
(a) During the day, ______ ions move into the guard cells.
(b) This increases the osmotic pressure of the guard cells, causing ______ of water into them.
(c) The guard cells become ______.
(d) The stomatal pore ______ due to the uneven thickening of the guard cell walls.
(e) At night, the ions move out and the guard cells become ______.
(iii) Choose the odd one out and name the category of the remaining three. [5]
(a) Neutrophils, Lymphocytes, Erythrocytes, Monocytes
(b) Testosterone, Oestrogen, Progesterone, Insulin
(c) Pinna, Tympanic membrane, Cornea, Eustachian tube
(d) Pituitary, Thyroid, Adrenal, Salivary gland
(e) Carbon dioxide, Methane, Nitrous oxide, Sulphur dioxide
(iv) Case study [5]
Karan finds it difficult to read the board in his classroom but can read his book comfortably. An eye test reveals that distant objects appear blurred to him.
(a) Name the defect of vision Karan is suffering from.
(b) State one reason for this defect.
(c) Name the type of lens used to correct it.
(d) Where is the image formed in the eye of Karan — in front of, on, or behind the retina?
(e) Name the muscles that change the curvature of the eye lens.
(v) Match the items in Column A with the descriptions in Column B. [5]
One example is given: Auxin – (f)
| Column A | Column B |
|---|---|
| Gibberellin | (a) Promotes cell division and delays the ageing of leaves |
| Cytokinin | (b) Stimulates the ripening of fruits |
| Abscisic acid | (c) Causes closure of stomata under water stress |
| Ethylene | (d) Coiling of tendrils around a support |
| Thigmotropism | (e) Promotes stem elongation and breaks seed dormancy |
| Auxin | (f) Promotes cell elongation (example) |
(Match each of Gibberellin, Cytokinin, Abscisic acid, Ethylene and Thigmotropism with the correct description.)
A student presses small pieces of dry blue cobalt chloride paper on the upper and lower surfaces of a dorsiventral leaf and covers each with a glass slide.
(i) What is the aim of this experiment? [1]
(ii) State the colour change observed in the paper and give a reason for it. [2]
(iii) On which surface of the leaf will the change occur faster? Give a reason. [2]
(iv) Why are the pieces of paper covered with glass slides? [2]
(v) Draw a neat, labelled diagram of the experimental set-up used to demonstrate transpiration using a bell jar. [3]
(i) Name the chamber of the human heart that pumps oxygenated blood to the entire body. [1]
(ii) Why is the wall of the left ventricle thicker than that of the right ventricle? [2]
(iii) Name the valve present between the left auricle and the left ventricle. State its function. [2]
(iv) What is meant by double circulation? State one advantage of it. [2]
(v) Draw a neat, labelled diagram of the human heart (vertical section). [3]
Seema, a school student, was feeling very thirsty and passing urine frequently. A urine test showed the presence of sugar.
(i) Name the disorder Seema is suffering from. [1]
(ii) Name the hormone whose deficiency causes this disorder and the gland which secretes it. [2]
(iii) Explain how insulin and glucagon together regulate the blood glucose level. [2]
(iv) State two differences between endocrine glands and exocrine glands. [2]
(v) State the effect of: [3]
(a) hyposecretion of thyroxine in childhood
(b) hypersecretion of growth hormone in adults
(c) hyposecretion of ADH
(i) Define reflex action. [1]
(ii) Write the path of the nerve impulse in a reflex arc. [2]
(iii) State the functions of (a) the cerebellum and (b) the medulla oblongata. [2]
(iv) Differentiate between a natural reflex and an acquired reflex, giving one example of each. [2]
(v) Draw a neat, labelled diagram of a neuron. [3]
(i) State the approximate duration of the human menstrual cycle. [1]
(ii) Name the hormone responsible for the development of secondary sexual characters in (a) males and (b) females. [2]
(iii) Explain the terms (a) implantation and (b) gestation. [2]
(iv) State any two functions of the placenta. [2]
(v) Draw a neat, labelled diagram of a human sperm. [3]
(i) Name the scientist who proposed the theory of inheritance of acquired characteristics. [1]
(ii) Explain the adaptation of the peppered moth as an example of natural selection. [2]
(iii) Mention any two trends observed in human evolution from Australopithecus to Homo sapiens. [2]
(iv) Define (a) demography and (b) population density. [2]
(v) State any three problems faced by a country as a result of population explosion. [3]