ICSE Class 10 Biology Solved Paper 2026

Four friends P, Q, R and S were discussing the examples of genetic disorders. The examples they quoted were as follows:

• P. Colour blindness and Malaria
• Q. Albinism and Cholera
• R. Haemophilia and Colour blindness
• S. Haemophilia and Albinism

Who gave the correct examples?

During the ventricular systole, the atrioventricular valves (P) …………… and the semilunar valves (Q) …………… .

Assertion (A): A thick cuticle reduces transpiration by acting as a barrier.

Reason (R): Desert plants have large, thin leaves for transpiration.

A sequence of DNA has 300 nitrogenous base pairs, of which 75 are Guanine. What is the number of Thymine in this sequence?

Assertion (A): Abscisic acid promotes stomatal closure during a drought.

Reason (R): Abscisic acid helps the plant to conserve water during stress.

Assertion (A): Leukoderma is the biological term for blood cancer.

Reason (R): An abnormal increase in the number of WBCs causes blood cancer.

A health organization wants to educate the rural audience about population control using visually engaging methods. Which of these would be effective?

• P. Posters
• Q. Loudspeakers
• R. Film shows
• S. Street plays

A family has a history of colour blindness. During genetic testing, it was found that the mother is a carrier of colour blindness (X^CX) and the father has normal vision (XY). What is the probability of their sons being colour-blind?

Bharat woke up late in the morning and missed the school bus.

This situation stimulated the nerves of the sympathetic system which resulted in

Which is the correct sequence of blood flow in the Pulmonary and Systemic circulation?

Karan was standing on a high stool and cleaning the ceiling fan.

He suddenly loses balance and sustains a head injury. An examination reveals that his pupils have lost the capacity to constrict in bright light. Which structure has been damaged?

A person suffering from kidney failure has proteins in the urine. What is this condition called?

What does Swachh Bharat Abhiyan aim to achieve in India?

Varun’s mother added plenty of salt to the mango pickle she made. This is to:

A. enhance the colour of the pickle.

B. inhibit the growth of microorganisms.

C. increase the nutritional value.

D. create a hypertonic solution.

During which phase of the menstrual cycle does the endometrium shed?

Give the biological/technical terms for the following:

(a) The tropic movement wherein the tendrils of a pea plant twine around a support.

(b) A defect in our eye in which some parts of the object are in focus while the other parts are blurred.

(c) The type of waste generated in hospitals and pathological laboratories.

(d) The surgical technique for females that can be used to prevent pregnancy.

(e) The evolutionary process by which new species arise from the existing one.

Given below is the diagram of a human sperm. Read the information below the diagram and fill in the blanks:

Living organisms reproduce to form new individuals of their own kind. This is essential for the survival and continuation of species. Human sperms are microscopic structures that carry genetic material.

The head of the sperm has a cap like organelle called (a) …………… (Lysosome / Acrosome) which produces an enzyme (b) …………… (Hyaluronidase / Amylase) that dissolves the outer layer of the ovum to facilitate fertilisation. The nucleus of the sperm has (c) …………… (23 / 46) chromosomes. The middle piece has (d) …………… (Chloroplast / Mitochondria) to provide energy for the motility of the sperm. (e) …………… (Semen / Hymen) is a mixture of sperms and the fluids produced by the male accessory glands.

Choose the odd one out from the following terms and name the category to which the others belong:

(a) Auxin, Oxytocin, Gibberellin, Cytokinin

(b) Growth Hormone, Vasopressin, Thyroid Stimulating Hormone, Gonadotropic Hormone

(c) Urochrome, Urea, Uric acid, Nucleic acid

(d) Cervix, Chordae Tendinea, Papillary Muscles, Sinoatrial node

(e) Morula, Blastocyst, Oviduct, Foetus

Mohit, a 30-year-old man was a software professional leading a sedentary life. He showed signs of high blood sugar during a routine health check-up despite having a normal body weight.

Answer the following:

(a) The hormonal disorder he is suffering from.

(b) The hormone responsible for this disorder.

(c) The organ that secretes this hormone.

(d) One symptom experienced by Mohit due to this disorder.

(e) One change in lifestyle to lower the blood sugar level.

Structures shown: Renal medulla, Renal artery, Renal vein, Pelvis, Ureter and Renal cortex.

Structure	Label	Function
	(a)	Has Malpighian capsules
	(b)	Carries oxygenated blood
	(c)	Transports urine to urinary bladder
	(d)	Has Henle’s loops
	(e)	Carries deoxygenated blood
	(f)	Receives urine which flows into ureter

Example: Pelvis – (f)

Which is the resting but metabolically active stage of the cell cycle?

Given below is the picture of an eagle.

Eagles have binocular vision. What is the advantage of such a vision?

Mention the number of Autosomes and Allosomes in a human body cell.

Two well-watered, identical plants were placed in brightly lit rooms at different temperatures — one at 15°C and the other at 38°C. The plant in the warmer room showed wilting by the end of the day.

(a) Which plant phenomenon resulted in the wilting of the leaves?

(b) Mention the factor of the phenomenon that is being tested.

Draw a neat, labelled diagram of an animal cell showing the Prophase stage of Mitosis with four chromosomes.

What is the scientific name of modern man?

How are the Cytons and Axons of neurons arranged in the following?

(a) Cerebrum

(b) Spinal cord

(a) Who proposed the theory of Natural Selection?

(b) Name the organism which was used as an example to explain Industrial Melanism.

Differentiate between Plasmolysis and Deplasmolysis.

Akshay’s father had a tumour in his prostate gland. His doctor advised him to get it removed surgically. One side effect of the surgery was incontinence of urine, i.e., leakage of urine from the urinary bladder.

(a) Where is the prostate gland located?

(b) Why does the prostate gland produce an alkaline secretion?

(c) Name the structure regulating the flow of urine from the bladder into the urethra.

RBCs do not have nuclei. Discuss its advantage.

Arrange the following food chains in a proper sequence.

(a) Small fish, Algae, Mosquito larvae, Kingfisher

(b) Frog, Snail, Crow, Green leaves

A 28-year-old pregnant lady goes to a gynecologist for a check-up. Her doctor explains that there is normal growth of the foetus and the placenta is functioning well.

(a) Mention one function of the placenta.

(b) What connects the placenta to the foetus?

Mention any two secondary sexual characteristics in a 15-year-old boy.

Tara’s grandmother is 70 years old and has a passion for embroidery. She faces difficulty in threading the needle as the eye of the needle appears blurred. The ophthalmologist diagnosed it as an age-related disorder.

(a) Name the defect.

(b) How can it be corrected?

(c) Where is the image formed in this defect?

Explain the term ‘Population Density’ with reference to human beings.

A 17-year-old girl has irregular menstrual cycles and symptoms of adrenal virilism.

(a) Hypersecretion of which hormone causes this condition?

(b) Mention one symptom of this condition.

Differentiate between Mitosis in plant cell and animal cell based on Cytokinesis.

Sara placed a healthy potted plant in a dark room for 48 hours to perform an experiment on photosynthesis. She plucked one of the leaves and tested it for starch. The leaf did not turn blue-black on adding Iodine solution.

(a) Why was the plant placed in the dark for 48 hours?

(b) What is the significance of boiling the leaf in alcohol?

Copy the diagram given below.

(a) Name the structure.

(b) Label Gray matter and White matter.

Write the overall chemical equation for photosynthesis.

Expand the abbreviations:

(a) NADP

(b) ADP

(a) Explain the term ‘Synapse’.

(b) Name the neurotransmitter that allows the transmission of impulses across the synapse.

What is the role of the following?

(a) Leydig cells

(b) Seminiferous tubules

“Vanishing Greenery; A Growing Urban Crisis”

In most of our cities, rapid urbanisation has led to a significant decrease in greenery over the past two decades. As the population increased, the demand for housing, roads and commercial buildings grew, leading to clearing of parks, gardens and natural resources. This has contributed to several problems.

(a) Mention one problem caused by the decrease in greenery.

(b) How do green plants improve air quality?

(c) What role can citizens play in addressing this problem?

Write the term for the pressure exerted by the cell contents on the cell wall.

(a) Name the fluid present between the meninges in spinal cord.

(b) What is its function?

Given below is the diagram of a turgid plant cell:

Copy the diagram and label Vacuole and Plasma membrane.

Select and write the two biodegradable wastes from the given list:

Styrofoam, Metallic cans, Decaying fruits, Plastic bottles, Newspapers

Rajat Singh was working as a supervisor in a stone quarry where rock, sand and gravel are extracted by techniques like digging, drilling and blasting. As the years rolled by, Rajat started facing a loss in hearing. The high decibel sounds had damaged a part of his internal ear, though the tympanic membrane was intact.

(a) What is the collective term for the structures of the internal ear?

(b) Name the sensory organ in the cochlea that was damaged.

(c) Name the type of pollution responsible for this condition.