Solved 2025 Specimen Paper ICSE Class 10 Biology

Renal Medulla

Reason — The Loops of Henle are structures within the kidneys that extend into the renal medulla.

Lysozyme

Reason — Lysozyme is an enzyme that plays a role in the immune system, particularly in defense against bacterial infections.

Both A and R are True

Reason — Respiration refers to the metabolic process by which cells break down nutrients (such as glucose) to produce energy, usually in the form of ATP (adenosine triphosphate). The foetus obtains oxygen and nutrients from the mother through the placenta.

P-close, Q-open

Reason — During ventricular systole, which is the phase of the cardiac cycle when the ventricles contract to pump blood out of the heart, the atrioventricular valves (P) closes and semilunar valves (Q) opens.

Corpus callosum

Reason — The corpus callosum is a thick band of nerve fibers that connects the two cerebral hemispheres of the brain. It facilitates communication between the left and right hemispheres.

Menarche

Reason — Menarche refers to the first occurrence of menstruation in girls, marking the onset of puberty and reproductive maturity.

A is False and R is True

Reason — Rods and cones are located in the retina, not the sclera.

P- Glucagon, Q- Vasopressin

Reason — Glucagon is a hormone produced by the pancreas that stimulates the conversion of glycogen (stored form of glucose in the liver) to glucose. Vasopressin, also known as antidiuretic hormone (ADH), is produced by the posterior lobe of the pituitary gland. It acts on the kidney increasing reabsorption of water by the nephrons.

Homo sapiens

Reason — A well-developed chin is a characteristic feature observed in Homo sapiens.

Homologous chromosomes

Reason — Homologous chromosomes are pairs of chromosomes that have the same genes at the same loci.

A is False and R is True

Reason — Urine output is less in summers as most of the water is lost in form of sweat.

Rupture of eardrum

Reason — Rupture of the eardrum, also known as tympanic membrane perforation, is a condition where there is a tear or hole in the thin membrane that separates the outer ear from the middle ear.

Both A and R are False

Reason — All food chains begin with producers i.e., green plants.

Raj and Lata

Reason — Wisdom teeth, Pinna and Vermiform appendix are vestigial organs whereas large intestine, ossicles and body hairs perform important functions in human body, hence, are not vestigial organs.

Hypertonic, Exosmosis

Reason — If the solution is hypertonic, exosmosis occurs i.e., the sap moves outward from the cell to the solution. This outward movement of cell sap leads to shrinking of cell.

(a) Genes

(b) Pollution

(c) Umbilical Cord

(d) Demography

(e) Thymine

The spinal cord is a part of the (a) Central Nervous System. The grey matter in the picture given above consists of (b) cytons while the white matter consists of (c) axons. The spinal cord is concerned with the (d) reflex actions below the neck. (e) Vertebral column is the bony structure that protects the spinal cord.

(a) Auxins, Apical meristem, Cell elongation, Positive phototropism

(b) Kidney, Ureter, Urinary bladder, Urethra

(c) Auditory canal, Malleus, Stapes, Organ of Corti

(d) Chromatin fibres, Cytoplasm, Cell membrane, Cell wall

(e) Inferior venacava, Right auricle, Pulmonary Artery, Lungs

(a) Phloem

(b) Zygote

(c) Capillaries

(d) Eustachian Tube

(e) Lenticels

(a) - 5. Transmits nerve impulses to brain

(b) - 1. Protects retina

(c) - 2. Regulates the size of the pupil

(d) - 4. Keeps the lens moist

(e) - 3. Alters the shape of the lens

Active transport is the passage of a substance (salt or ion) from its lower to higher concentration through a living cell membrane using energy from the cell.

Transpiration occurs through stomata, lenticel and cuticle. Guttation occurs through hydathodes.

(a) High temperature — The rate of transpiration increases with increase in temperature.

(b) High humidity — The rate of transpiration decreases with increase in humidity.

$6\text{CO}_2 + 12\text{H}_2\text{O} \xrightarrow[\text{chlorophyll}]{\text{light energy}} \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{H}_2\text{O} + 6\text{O}_2 \uparrow$

(a) Stomata

(b) Guard cells

(c) Potassium ions

Adrenaline is known as the Emergency hormone because it prepares the body to meet any emergency situation, for "fight" i.e. to face danger or for "flight" i.e. to run away from it. Extra energy and strength is provided to the body in that situation. It stimulates the sympathetic nervous system. When excited or angry, the adrenal medulla produces a lot of Adrenaline preparing the body for any emergency.

ADH stands for Antidiuretic Hormone. One example of a diuretic substance is caffeine.

(a) Iodine is required for the synthesis of thyroxine by thyroid gland.

(b) Magnesium is required for the synthesis of chlorophyll.

Two objectives of Swachh Bharat Abhiyan are:

1. To eliminate open defecation: The mission aims to ensure that all households have access to toilets and promote the construction and use of sanitary latrines.
2. To promote cleanliness and hygiene: It seeks to create awareness about sanitation and cleanliness practices, improve waste management systems, and maintain cleanliness in public spaces.

Labelled diagram of a root hair is given below:

One characteristic of roots for absorbing water from the soil is presence of thin cell walls in root hairs. This allows easy entry of water in the root hairs from the soil.

Parthenocarpy is a phenomenon in plants where fruits develop without fertilization of ovules. In other words, fruits are formed without the need for pollination and fertilization. One example of a parthenocarpic fruit is the banana.

The two key functions of lymph are:

1. It drains excess tissue fluid into blood.
2. Fats from the intestine are absorbed through lymphatics.

(a) Water gets polluted due to:

• Factories and industrial facilities releasing pollutants such as chemicals, heavy metals, and toxins into water bodies.
• Pesticides, herbicides, and fertilizers used in agriculture can wash into rivers, lakes, and streams through runoff, especially after heavy rainfall.

(b) Contaminated water can carry pathogens such as bacteria, viruses, and parasites that cause waterborne diseases like cholera, dysentery, hepatitis A, and giardiasis. Long-term exposure to polluted water containing harmful chemicals, such as heavy metals (e.g., lead, mercury) and industrial pollutants, can result in chronic health issues.

(c) By ensuring that all industrial, agricultural, and municipal wastewater is properly treated before being released into water bodies, harmful pollutants and contaminants can be significantly reduced.

During the formation of gametes (sperm or eggs), the two alleles for a given gene separate, or segregate, so that each gamete carries only one allele for each gene. When gametes fuse during fertilization, the resulting offspring inherits one allele from each parent, restoring the diploid number of alleles for that gene.

Tropic hormones are hormones that stimulate other endocrine glands to produce and release their hormones. They act on target glands rather than directly on tissues or organs. Tropic hormones play a crucial role in regulating various physiological processes by controlling the activity of other endocrine glands. For example: TSH (Thyroid Stimulating Hormone) activates thyroid to secrete thyroxin.

Testes are responsible for the production of male gametes i.e., sperms. The normal body temperature does not allow the maturation of the sperms. Being suspended outside the body cavity, the temperature in the scrotal sac is 2 to 3°C lower than that of the body which is the suitable temperature for the maturation of the sperms.

Labelled diagram of a human sperm is shown below:

Pisum Sativum

(a) Men - Vasectomy

(b) Women - Tubectomy

Two harmful effects of noise pollution are:

• Disturbs sleep.
• Interrupts concentration of thoughts

(a) Negative Geotropism - Shoot

(b) Positive Hydrotropism - Root

(a) Semicircular canal

(b) The fluid in the semi-circular canals continue to spin for a short time even after the dancer stops. This results in dizziness.

(c) Auditory nerve

Transpiration is the process by which water is lost from the plant, primarily through small openings called stomata on the leaves. As water evaporates from the leaf surfaces, it creates a negative pressure (or suction) within the leaf's xylem vessels. This negative pressure in the leaf creates a "suction effect" that pulls water upward from the roots through the xylem vessels.

(a) Freshwater fish when placed in a hypertonic salt solution lose water and may shrink.

(b) Seminiferous tubules are involved in the production of sperm, while testosterone is secreted by the interstitial cells (Leydig cells) in the testes.

(a) Metaphase - In the equatorial plane.

(b) Anaphase - Sister chromatids separate and move towards opposite poles.

(a) Conjunctiva → Cornea → Pupil → Lens → Fovea

(b) Optic Nerve.

Below labelled diagram shows Malpighian Capsule: