Complete ICSE Class X Biology 2024 question paper with accurate, step-by-step solutions.
(Attempt all questions from this section)
Duplicated chromosomes are joined at a point termed:
(b) Centromere
Explanation: Duplicated chromosomes (sister chromatids) are joined at a point termed the centromere.
The process of conversion of ADP to ATP during photosynthesis is called:
(c) Photophosphorylation
Explanation: Photophosphorylation is the synthesis of ATP from ADP and inorganic phosphate using light energy during photosynthesis.
The process by which water is lost from the margins of the leaves of a strawberry plant is:
(d) Guttation
Explanation: Guttation is the exudation of water droplets from the tips or margins of leaves through hydathodes.
Which of the following hormones will have an immediate effect on the rate of urination?
(b) Vasopressin
Explanation: Vasopressin, also called antidiuretic hormone (ADH), increases the reabsorption of water by the kidneys and therefore affects the rate of urination.
Which of the following helps in the opening of stomata?
(b) Potassium ions
Explanation: Potassium ions enter the guard cells, causing water to enter by osmosis. The guard cells become turgid and the stomata open.
A zygote which has an Y chromosome inherited from the father will develop into:
(d) Boy
Explanation: A child always inherits an X chromosome from the mother. If the father contributes a Y chromosome, the zygote has XY chromosomes and develops into a boy.
Which ear ossicle transports sound from the tympanum to the inner ear?
(a) Stapes
Explanation: The stapes transmits vibrations through the oval window to the inner ear. It is the innermost of the three ear ossicles.
The immediate steps to be taken when a person suffers a heart attack are:
(d) P, Q and R
Explanation: The person should be made comfortable by loosening clothes and making them lie down in an airy place, and must be taken to a hospital immediately. Conversation should not be encouraged because it may cause exertion.
Which part of the eye adjusts the focal length of the eye lens?
(c) Ciliary muscles
Explanation: The ciliary muscles contract or relax to change the curvature and focal length of the eye lens, enabling the eye to focus on objects at different distances.
Which of the following sets shows examples of genetic disorders?
(b) R and S
Explanation: Haemophilia, colour blindness and albinism are genetic disorders. Malaria and cholera are infectious diseases and are not inherited genetic disorders.
Osmosis involves the movement of water molecules through a:
(c) Selectively permeable membrane
Explanation: Osmosis is the movement of water molecules from a region of higher water concentration to a region of lower water concentration through a selectively permeable membrane.
A male gorilla has 48 chromosomes in each body cell. How many chromosomes will be present in each of its sperms?
(a) 24
Explanation: Body cells are diploid, whereas gametes are haploid. Therefore, each sperm has half of 48 chromosomes, that is, 24 chromosomes.
Assertion: The sympathetic nervous system prepares the body for violent action.
Reason: The sympathetic nervous system accelerates the heartbeat.
(a) Both Assertion and Reason are true.
Explanation: The sympathetic nervous system produces the fight-or-flight response. It accelerates the heartbeat so that more oxygenated blood reaches the muscles during an emergency.
Birth rate is the number of live births per thousand persons in:
(a) 1 year
Explanation: Birth rate is defined as the number of live births per 1,000 people in a population in one year.
Industrial melanism was observed in:
(b) Peppered Moth
Explanation: Industrial melanism was observed in the peppered moth during the Industrial Revolution in England, when natural selection favoured dark-coloured moths in polluted areas.
Name the following:
(a) Unicellular outgrowths of the epidermis of roots.
(b) The defect of the eye in which some parts of an object are focused while other parts appear blurred.
(c) The tropic movement in response to chemicals.
(d) The main nitrogenous waste in the human body.
(e) The attachment of the fertilized ovum to the wall of the uterus.
(a) Root hairs
(b) Astigmatism
(c) Chemotropism
(d) Urea
(e) Implantation
Arrange the following in a logical sequence:
(a) Australopithecus, Cro-Magnon, Homo erectus, Neanderthal man.
(b) Pupil, Aqueous humour, Retina, Vitreous humour.
(c) Effector, Receptor, Motor neuron, Sensory neuron.
(d) Loop of Henle, Distal convoluted tubule, Bowman’s Capsule, Proximal convoluted tubule.
(e) Water vapour, Soil water, Leaves, Ascent of Sap.
(a) Australopithecus → Homo erectus → Neanderthal man → Cro-Magnon
(b) Aqueous humour → Pupil → Vitreous humour → Retina
(c) Receptor → Sensory neuron → Motor neuron → Effector
(d) Bowman’s Capsule → Proximal convoluted tubule → Loop of Henle → Distal convoluted tubule
(e) Soil water → Ascent of Sap → Leaves → Water vapour
Study the diagram given below and fill in the blanks with suitable words:
In order to prove that carbon dioxide is necessary for (a) …………… , a potted plant is placed in dark for 48 hours to (b) …………… the leaves. A part of a leaf is inserted into a conical flask containing potassium hydroxide solution. This is to absorb (c) …………… from the flask. The plant is then placed in sunlight for a few hours. The experimental leaf is tested for starch. The part of the leaf that was inside the conical flask turns (d) …………… , whereas the part of the leaf outside turns (e) …………… in colour.
(a) Photosynthesis
(b) Destarch
(c) Carbon dioxide
(d) Brown
(e) Blue-black
Pick the odd one out and name the category to which the remaining three belong:
(a) Prothrombin, Thrombin, Fibrinogen, Albumin
(b) Tonsils, Glomerulus, Spleen, Lymph nodes
(c) Neutrophils, Basophils, Monocytes, Eosinophils
(d) Leaves, Styrofoam, Grass, Cow dung
(e) Pulmonary artery, Renal artery, Coronary artery, Hepatic artery
| Part | Odd one out | Category of the remaining three |
|---|---|---|
| (a) | Albumin | Substances involved in blood clotting |
| (b) | Glomerulus | Parts of the lymphatic system |
| (c) | Monocytes | Granular white blood cells (granulocytes) |
| (d) | Styrofoam | Biodegradable materials |
| (e) | Pulmonary artery | Arteries carrying oxygenated blood |
Match the items in Column I with those in Column II:
| Column I | Column II |
|---|---|
| Leydig cells | Lack of thyroxine in children |
| Stoma | 12 pairs |
| Ova | Testosterone |
| Cranial nerve | Diffusion of respiratory gases |
| Cretinism | Haploid cells |
| 31 pairs | |
| Diploid cells |
| Column I | Correct match |
|---|---|
| Leydig cells | Testosterone |
| Stoma | Diffusion of respiratory gases |
| Ova | Haploid cells |
| Cranial nerve | 12 pairs |
| Cretinism | Lack of thyroxine in children |
(Attempt any four questions)
Expand the abbreviation-NADP.
NADP – Nicotinamide Adenine Dinucleotide Phosphate.
Mention two adaptations in roots for absorption of water from the soil.
Two adaptations in roots for absorption of water from the soil are:
Differentiate between Afferent arteriole and Efferent arteriole (diameter).
| Afferent arteriole | Efferent arteriole |
|---|---|
| This arteriole is larger in diameter compared to the efferent arteriole. | This arteriole is smaller in diameter compared to the afferent arteriole. |
Give two examples of water pollutants.
Two examples of water pollutants are:
Ali has some pea plants in his garden which need a support to grow as seen in the picture given below:
(a) Name the phenomenon depicted by the shoot in the given figure.
(b) Define the above phenomenon.
(c) Write the name of the part marked X.
(a) Thigmotropism.
(b) The growth movement of plant parts in response to touch stimulus is called Thigmotropism.
(c) X → Leaf Tendril
Give the biological term for the surgical method of contraception in human females.
Tubectomy.
State two harmful effects of acid rain on the environment.
Two harmful effects of acid rain on the environment are:
Mention two advantages of Transpiration.
Two advantages of transpiration are:
Write any two objectives of Swachh Bharat Abhiyan.
Two objectives of Swachh Bharat Abhiyan (Clean India Mission) are:
Mohan is fond of playing basketball. His concentration is on shooting the ball into the opponent’s basket as given in the picture.
(a) Which part of the brain helps Mohan to concentrate in putting the ball into the basket?
(b) Name the sense organ that helps to gauge the distance between the ball and the basket.
(c) Name the part of the brain that co-ordinates all the voluntary muscles of his body.
(a) Frontal lobe or cerebral cortex.
(b) Eyes.
(c) Cerebellum.
Name the type of nerve which has the fibres of both sensory and motor neurons.
Mixed nerve.
Differentiate between Australopithecus and Modern man based on body hair.
| Australopithecus | Modern man |
|---|---|
| Body hair covered much of the body of Australopithecus. | Modern man has highly reduced body hair. |
“Birth rate in India is very high.” Mention two reasons in support of the statement.
The birth rate in India is very high because:
Give the exact location of:
(a) Pericardium
(b) Bicuspid valve
(a) Pericardium — Protective double-walled membranous covering that surrounds the heart.
(b) Bicuspid valve — Located between the left atrium and the left ventricle of the heart.
Given below is a schematic representation of the inheritance of the shape of seeds of garden pea. Answer the questions that follow:
(a) Which is the dominant and recessive allele of the trait?
(b) What does the ratio 3 : 1 in the F₂ generation represent?
(c) State Mendel’s Law of Dominance.
(a) The allele for smooth seeds is dominant over the allele for wrinkled seeds, which is recessive.
(b) The ratio 3 : 1 represents the phenotypic ratio in the F₂ generation. Approximately three individuals show the dominant phenotype for every one individual showing the recessive phenotype.
(c) Out of a pair of contrasting characters present together, only one is able to express itself while the other remains suppressed. The one that expresses itself is the dominant character and the one that remains unexpressed is the recessive character.
Define the term-Diapedesis.
Diapedesis is the process by which white blood cells (WBCs) squeeze through capillary walls into tissues, using amoeboid-like extensions called pseudopodia to reach sites of infection or inflammation.
Distinguish between Diabetes mellitus and Diabetes insipidus (endocrine gland concerned).
| Diabetes mellitus | Diabetes insipidus |
|---|---|
| Islets of Langerhans of the pancreas are concerned with Diabetes mellitus. | Posterior lobe of the pituitary gland is concerned with Diabetes insipidus. |
Carbon monoxide is dangerous when inhaled in excess. Comment on the statement.
Haemoglobin has a very strong affinity for carbon monoxide and forms a stable compound called carboxyhaemoglobin. This reduces the capacity of blood to transport oxygen and may result in death. Hence, carbon monoxide is highly dangerous when inhaled in excess.
The diagram given below shows a section of the human ovary.
(a) Name the process for the release of the part labelled 1.
(b) Write the name of the structure marked 2.
(a) Ovulation
(b) Corpus luteum
Draw a neat, labelled diagram of a chloroplast.
A neat, labelled diagram of a chloroplast should show the outer membrane, inner membrane, stroma, grana and stroma lamellae.
Define the term hormone.
A hormone is a secretion from some glandular part of the body, which is poured directly into the blood and acts on the target organs or cells of the same individual, bringing about coordination between distant parts of the body.
Which parts of the ear are responsible for:
(a) Static equilibrium?
(b) Dynamic equilibrium?
(a) Static equilibrium — Vestibule
(b) Dynamic equilibrium — Semicircular canals
Mention two structural differences between an artery and a vein.
| S. No. | Arteries | Veins |
|---|---|---|
| 1. | Arteries have thick and muscular walls. | Veins have thin and less muscular walls. |
| 2. | Arteries have a narrower lumen. | Veins have a wider lumen. |
Write any two limitations of using a Ganong’s Potometer to demonstrate the uptake of water.
Two limitations of using a Ganong’s Potometer to demonstrate the uptake of water are:
A teacher drew the diagram of heart on the blackboard and told the students to copy it in their notebooks. Mahesh couldn’t see the diagram clearly as it appeared blurred to him.
(a) Name the defect of the eye Mahesh is suffering from.
(b) Where is the image formed in this defect?
(c) Mahesh consults an eye doctor and is prescribed suitable lenses to correct the defect. Which type of lens do his spectacles have?
(a) Mahesh is suffering from myopia, also known as nearsightedness.
(b) In myopia, the image is formed in front of the retina instead of directly on the retina.
(c) To correct myopia, Mahesh would need concave lenses.
Define the term ultrafiltration.
The blood flows through the glomerulus under great pressure, which causes the liquid part of the blood to filter out from the glomerulus into the renal tubule. This filtration under high force is called ultrafiltration.
Name the mineral elements required for:
(a) Clotting of blood
(b) Synthesis of thyroxine
(a) Clotting of blood — Calcium
(b) Synthesis of thyroxine — Iodine
Mention two harmful effects of noise pollution.
Two harmful effects of noise pollution are:
Why are RBCs efficient in their functions though they lack nucleus and mitochondria?
RBCs are efficient in their functions though they lack nucleus and mitochondria because:
The diagram given below 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) Early Anaphase
(b) In Early Anaphase, the sister chromatids separate and start moving towards the opposite poles due to the contraction of spindle fibres.
(c) There are four chromosomes in the given diagram.
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