ICSE Class 10 Biology Important Questions 2027 (Repeated in Board Exams)

Draw a neat, labelled diagram of an animal cell having 4 chromosomes in the metaphase stage.

A pair of corresponding chromosomes of the same shape, size and one from each parent is called: (a) Autosomes (b) Allosomes (c) Analogous chromosomes (d) Homologous chromosomes

Synthesis phase in the cell cycle is called so, because of the synthesis of more: (a) Glucose (b) Proteins (c) RNA (d) DNA

Differentiate between Karyokinesis and Cytokinesis.

The diagram represents a stage in mitosis. (a) Identify the stage given above. (b) Give one reason to support your answer in (a). (c) Mention the number of chromosomes given in the diagram.

A male gorilla has 48 chromosomes in each of its body cells. How many chromosomes will each of the sperms have? (a) 24 (b) 48 (c) 12 (d) 16

A sequence of DNA has 300 nitrogenous base pairs, of which 75 are Guanine. What is the number of Thymine in this sequence? (a) 150 (b) 100 (c) 50 (d) 75

Read the explanation and name the structure: The point of attachment of two chromatids of a chromosome.

Mention the two pairs of nitrogenous bases that are present in a DNA strand and pair with each other by hydrogen bonds.

State Mendel's Law of Segregation of gametes.

Differentiate between the terms Phenotype and Genotype.

Give the common name and the scientific name of the plant on which Gregor Mendel conducted his breeding experiments.

State Mendel's Law of Dominance.

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

Name the following: The basic units of heredity.

Name the following: The type of gene, which in the presence of a contrasting allele, is not expressed.

A family has a history of colour blindness. The mother is a carrier (Xc X) and the father has normal vision (XY). What is the probability of their sons being colour blind? (a) 25% (b) 50% (c) 75% (d) 0%

Four friends P, Q, R and S discussed examples of genetic disorders. P. Colour blindness and Malaria Q. Albinism and Cholera R. Haemophilia and Colour blindness S. Haemophilia and Albinism. Who gave the correct examples? (a) P and Q (b) R and S (c) P and R (d) Q and S

Root hairs are epidermal outgrowths well suited for absorption of water due to: P - Large surface area, Q - Lower concentration of cell sap, R - Higher concentration of cell sap, S - Freely permeable cell membrane. (a) P and S (b) Q and S (c) P and R (d) R and S

Meena's mother prepared a cucumber salad garnished with salt and pepper. After some time a lot of water accumulated in the salad bowl. The cucumber slices underwent: (a) active transport (b) transpiration (c) exosmosis (d) endosmosis

Draw a neat, labelled diagram to show the internal structure of a root hair.

Arrange and rewrite the terms in correct logical sequence beginning with the underlined term: Endodermis, Cortex, Xylem, Epidermis.

State the permeability of cell membrane and cell wall.

Hari placed a salt water clown fish in a freshwater aquarium and after a few hours it was found dead and floating. This was due to: (a) Endosmosis (b) Exosmosis (c) Osmoregulation (d) Excretion

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. (a) A and C (b) B and C (c) C and D (d) B and D

Explain the term - Active transport.

Explain how the process (transpiration) will differ on a rainy day.

Avinash placed a potted plant on a windowsill on a hot summer morning; the leaves wilted though the soil was well watered, and regained turgidity indoors. Name the process responsible for the wilting of leaves.

Give the biological/technical term: Respiratory openings present on the stems of woody plants.

List three adaptations in plants to reduce this process (transpiration).

The process in which water is lost from the margins of strawberry leaves is: (a) Osmosis (b) Imbibition (c) Diffusion (d) Guttation

Meena covered a potted plant with a transparent plastic bag and observed water droplets inside the bag after a few hours in sunlight. (a) Name the process that resulted in the formation of water droplets inside the bag. (b) Define the process mentioned above.

Define the above process (responsible for wilting of leaves).

Write the balanced equation for photosynthesis. Name the mineral element essential for the formation of chlorophyll.

A potted plant under a bell jar with a watch glass containing potassium hydroxide is placed in sunlight for three hours; after exposure none of the leaves of plant X turned blue black with iodine, while control plant Y did. What is the aim of the experiment?

A potted plant with variegated leaves was kept in dark for 24 hours then placed in bright sunlight. Answer: (a) Which aspect of photosynthesis is being tested? (b) Why was the plant kept in dark for 24 hours? (c) After the starch test what will be the colour of the yellow and green parts of the leaf? Give reasons.

Give the biological/technical term: The ground substance present in a chloroplast.

Study the diagram (aquatic plant releasing gas in sunlight). (a) Name the gas released when the setup was placed in sunlight. (b) Give an example of an aquatic plant that can be used in the above experiment. (c) What will happen if a pinch of Sodium bicarbonate is added to the water?

Expand the abbreviations: (a) NADP (b) ADP.

The site of light reaction in the cells of a green leaf is: (a) Nucleus (b) Grana of chloroplast (c) Cytoplasm (d) Stroma of chloroplast

Study the diagram (potted plant bending towards sunlight). (a) Name the phenomenon depicted by the shoot. (b) Which plant hormone plays an important role in the above movement? (c) Name one stimulus which gives a positive response for the roots but negative response for the shoot.

What is Parthenocarpy? Give one example.

A farmer notices that storing ripe mangoes with unripe ones speeds up the ripening process. The phytohormone primarily responsible is: (a) Auxins (b) Cytokinins (c) Gibberellins (d) Ethylene

Choose the odd one out and name the category to which the others belong: Auxin, Oxytocin, Gibberellin, Cytokinin.

Ali has some pea plants which need a support to grow. (a) Name the phenomenon depicted by the shoot. (b) Define the above phenomenon. (c) Write the name of the part marked X.

The diagram shows a type of tropism (pollen tube growing towards the ovule). (a) Name the type of tropism. (b) Define the above mentioned tropism. (c) Give an example of a stimulant that helps in the growth of the part marked A.

Diagram of human blood smear. (a) Mention one structural difference between 1 and 2. (b) What is the function of part 3? (c) Name the part labelled 4.

The path of blood flow during pulmonary circulation is: (a) Right auricle, Right ventricle, Pulmonary artery, Lungs, Pulmonary veins, Left auricle. (b) Left auricle, Left ventricle, Pulmonary veins, Lungs, Pulmonary artery, Right auricle. (c) Left auricle, Left ventricle, Aorta, Tissues, Vena cava, Right auricle. (d) Right auricle, Right ventricle, Pulmonary veins, Lungs, Pulmonary artery, Left auricle.

Choose the ODD term out and mention the category to which the remaining three belong: Haemoglobin, Fibrin, Prothrombin, Fibrinogen.

Choose the ODD term out and mention the category to which the remaining three belong: Neutrophil, Monocyte, Eosinophil, Basophil.

Draw a neat, labelled diagram of a cross section of an Artery and a Vein.

Diagram of a human heart. Fill in the blanks: The heart is enclosed by a membrane called (a) ______ (Pericardium/Pleura). The ventricles give rise to two large blood vessels called (b) ______ (Pulmonary vein/Pulmonary artery) and (c) ______ (Aorta/Venacava). The flaps of the cuspid valves are kept in position by (d) ______ (Chordae tendinae/Endometrium). (e) ______ (Hepatic/Coronary) arteries supply oxygenated blood to the walls of the heart.

During the ventricular systole, the atrioventricular valves (P) ______ and the semilunar valves (Q) ______. (a) P - close and Q - open (b) P - close and Q - close (c) P - open and Q - close (d) P - open and Q - open

Mention two structural differences between an artery and a vein.

RBCs do not have nuclei. Discuss its advantage.

What is Excretion?

Mention the regions of the kidney where we can find glomerulus and Henle's loop.

Which parts of the nephron are present in the renal cortex and renal medulla? (a) Renal Cortex - 1, 2, 3; Renal Medulla - 4, 5, 6, 7 (b) Renal Cortex - 1, 2, 3, 4, 5; Renal Medulla - 6, 7 (c) Renal Cortex - 4, 5, 6, 7; Renal Medulla - 1, 2, 3 (d) Renal Cortex - 1, 2, 3, 4; Renal Medulla - 5, 6, 7

Assertion (A): We urinate more in summer. Reason (R): Sweat glands are more active in summer. (a) A is True and R is False (b) A is False and R is True (c) Both A and R are True (d) Both A and R are False

Choose the odd term out and mention the category to which the remaining three belong: Ureter, Urethra, Uterus, Renal Pelvis.

Choose the odd one out and name the category to which the others belong: Urochrome, Urea, Uric acid, Nucleic acid.

Which part of the ear equalizes air pressure on either side of the ear drum? Where is this structure located?

Assertion (A): Rods and Cones are photoreceptors in the sclera of eyeball. Reason (R): Rods are sensitive to dim light. (a) A is True and R is False. (b) A is False and R is True. (c) Both A and R are True. (d) Both A and R are False.

Arrange and rewrite the terms in correct logical sequence beginning with the underlined term: Auditory canal, Organ of Corti, Stapes, Malleus.

Cross section of the human eye. Match the structures marked (a) to (e) with their correct functions: Functions - 1. Protects retina 2. Regulates the size of the pupil 3. Alters the shape of the lens 4. Keeps the lens moist 5. Transmits nerve impulses to brain 6. Holds the lens in position.

What is the reason for Hyperopia? How can it be corrected?

Give the biological/technical term: The neurotransmitter stored in the axon endings of neurons.

(a) Name the fluid present between the meninges in spinal cord. (b) What is its function?

Rahul inserted a hairpin into his right ear to remove ear wax. He felt a sudden sharp pain with loss of hearing. This was due to: (a) Rupture of eardrum (b) Rupture of vestibule (c) Rupture of cornea (d) Rupture of pinna

Bharat woke up late and missed the school bus. This situation stimulated the nerves of the sympathetic system which resulted in: (a) Constriction of Coronary arteries (b) Muscle relaxation (c) Decrease in Respiration rate (d) Bronchodilation

Copy the diagram (transverse section of spinal cord). (a) Name the structure. (b) Label Gray matter and White matter.

Arrange and rewrite the terms in correct logical sequence beginning with the underlined term: Pupil, Aqueous humour, Retina, Vitreous humour.

Ayush was focussing intently on the strokes of the opponent player in a carrom match. (a) Which part of the brain helps Ayush to focus on the game? (b) Name the part of the brain that co-ordinates his muscles while using the striker.

Rachna, an expert gymnast on the balance beam, has been experiencing dizziness and losing her balance. (a) Which part of the membranous labyrinth is responsible for maintaining the body balance on the beam? (b) Which type of balance is maintained by the structure mentioned in (a)?

Mention the exact location of Corpus callosum.

Mahesh couldn't see the blurred diagram clearly. (a) Name the defect of the eye Mahesh is suffering from. (b) Where is the image formed in this defect? (c) Which type of lens do his spectacles have?

Give the biological/technical term: A defect in our eye in which some parts of the object are in focus while the other parts are blurred.

Mention one function each for - Cerebrum and Cerebellum.

Adjusting the focal length of the eye lens to view objects at different distances is done by: (a) Cornea (b) Iris (c) Ciliary muscles (d) Sclera

Name the following: The ear ossicle which opens into the oval window of Cochlea.

Arrange and rewrite the terms in correct logical sequence beginning with the underlined term: Effector, Receptor, Motor neuron, Sensory neuron.

Which parts of the ear are responsible for: (a) Static equilibrium? (b) Dynamic equilibrium?

Pallavi, a 30-year-old woman, showed male characteristics such as growth of moustache, beard and chest hair, diagnosed as a hormonal disorder. Mention the biological term for the disorder.

Mention the significance of the following minerals: (a) Iodine in our food. (b) Magnesium for green plants.

Reena gets emotionally stressed when the school examinations are approaching. Which hormone is responsible for this condition? (a) Adrenaline (b) Thyroxine (c) Insulin (d) Growth hormone

Choose the ODD term out and mention the category to which the remaining three belong: TSH, ADH, ACTH, FSH.

Explain the term hormone.

Differentiate between Diabetes mellitus and Diabetes insipidus with reference to the hormone involved.

Alpha cells of Pancreas secrete: (a) Glycogen (b) Glucose (c) Glucagon (d) Insulin

The onset of menstruation in a human female is called: (a) Menopause (b) Menarche (c) Ovulation (d) Oogenesis

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

State one difference between identical twins and fraternal twins.

A 28-year-old pregnant lady is told the foetus is growing normally and the placenta is functioning well. (a) Mention one function of the placenta. (b) What connects the placenta to the foetus?

Give the biological/technical term: The canal through which the testes descend into the scrotum just before the birth of a male baby.

Arrange the terms in correct logical sequence beginning with the underlined term: Sperm duct, Seminiferous tubule, Epididymis, Efferent ducts.

What is the role of the following? (a) Leydig cells (b) Seminiferous tubules.

Choose the odd one out and name the category to which the others belong: Morula, Blastocyst, Oviduct, Foetus.

Differentiate between Menarche and Menopause.

What is the significance of Testes being placed in Scrotal sacs?

Mention any two functions of amniotic fluid.

Mention two reasons for population explosion in India.

Explain the term Natality.

Name the following: The statistical study of human population.

List any three resources that come under pressure due to rising population.

Mention the surgical methods of contraception in: (a) Men (b) Women.

Give the biological/technical term: The surgical technique for females that can be used to prevent pregnancy.

Explain the term 'Population Density' with reference to human beings.

Choose the ODD term out and mention the category to which the remaining three belong: Wisdom tooth, Pinna, Tongue, Vermiform appendix.

Mention two characteristic features of Australopithecus.

Industrial melanism is the phenomenon by which the peppered moth: (a) die due to industrial growth. (b) in polluted areas, became darker in colour for better camouflage. (c) became lighter in colour due to natural selection. (d) became resistant to industrial pollution.

Who proposed the theory of 'Natural Selection'?

What is the scientific name of modern man?

Give any two characteristic features of a Cro-Magnon man.

What does Swachh Bharat Abhiyan aim to achieve in India? (a) Increase in deforestation to dump waste. (b) Expansion of landfill areas to accommodate more waste. (c) Improved sanitation and solid waste management. (d) Greater industrial waste production.

Study the picture (waste bin with gloves, syringes, tablets). (a) Name the category of waste that is being disposed. (b) Give an example of such a waste. (c) Are they hazardous to humans and animals? Give a suitable reason to justify your answer.

State any two disadvantages of living close to an airport.

Select and write the two biodegradable wastes from the given list: Styrofoam, Metallic cans, Decaying fruits, Plastic bottles, Newspapers.

State any two harmful effects of acid rain.

For the past few years there has been irregular rainfall, leading to crop failures and water shortages. This is a result of: (a) climate change (b) soil erosion (c) earth rotation (d) acid rain

Name the following: The undesirable change in the environment leading to its deterioration.

Choose the odd term out and mention the category to which the remaining three belong: Sulphur dioxide, Oxygen, Carbon monoxide, Nitrogen dioxide.

Give two examples of water pollutants.

Which one of the following is a biodegradable waste? (a) Metal cans (b) E-waste (c) Plastic (d) Flowers