ICSE Biology Specimen Paper – Key Vocabulary

A set of vocabulary flashcards summarising essential terms and definitions drawn from the ICSE 2026 Biology Specimen Question Paper and marking scheme.

Erythropenia

An abnormal decrease in the number of red blood cells (RBCs) in the blood.

Ethylene

A gaseous plant hormone that accelerates the ripening of fruits such as mangoes.

Photolysis

Light-driven splitting of water molecules during photosynthesis, releasing oxygen.

Adrenaline

A hormone secreted by the adrenal medulla that prepares the body for ‘fight-or-flight’ and is elevated during emotional stress.

Neutrophil

A type of white blood cell whose main function is phagocytosis of pathogens.

Phagocytosis

The engulfing and digestion of microbes or particles by certain cells, especially neutrophils and macrophages.

Pituitary gland

Endocrine ‘master gland’ that secretes hormones regulating other endocrine glands.

Reflex action

A rapid, involuntary response to a stimulus that requires no conscious thought.

Industrial melanism

Evolutionary phenomenon where darker varieties of organisms, such as the peppered moth, become common in polluted areas for better camouflage.

Progesterone

Ovarian hormone that maintains the thickened endometrium during pregnancy.

Menarche

The first occurrence of menstruation in a female, marking onset of reproductive capability.

Autosomes

The 22 pairs of non-sex chromosomes present in human body cells.

Allosomes

The one pair of sex chromosomes (XX or XY) in humans.

Smog

A harmful mixture of smoke and fog found in polluted air.

Endometrium

The inner lining of the uterus that thickens and sheds during the menstrual cycle.

Root pressure

Hydrostatic pressure that pushes water upward through a plant’s xylem from the roots.

Stroma (chloroplast)

The protein-rich ground substance inside a chloroplast where the Calvin cycle occurs.

Cerebrospinal fluid (CSF)

The fluid located between the meninges layers that cushions the brain and spinal cord.

Tears

Lubricating fluid that bathes and protects the eye surface.

Cones

Photoreceptor cells in the retina responsible for colour vision.

Optic nerve

The cranial nerve that transmits visual impulses from the retina to the brain.

Iris

Pigmented muscular structure that gives the eye its colour and controls pupil size.

Pupil

The opening in the centre of the iris through which light enters the eye.

Scrotum

Skin pouch that holds the testes outside the body and regulates their temperature.

Interstitial cells (Leydig cells)

Cells in the testes that secrete the male hormone testosterone.

Efferent ducts

Small ducts that transport sperm from the testis to the epididymis.

Epididymis

Coiled tube on the testis where sperm mature and are stored.

Vas deferens

Duct that transports sperm from epididymis to urethra during ejaculation.

Seminiferous tubules

Highly coiled structures in the testes where sperm are produced.

Guttation

Loss of water from plant leaves in the form of droplets, usually through hydathodes.

Transpiration

Evaporation of water vapour from aerial parts of a plant, mainly through stomata.

Cerebrum

Largest brain region responsible for conscious thought, memory and voluntary actions.

Cerebellum

Brain region that coordinates muscular movements and maintains balance.

Cell membrane

Semipermeable membrane surrounding the cell, controlling substance movement.

Cell wall

Freely permeable outer layer of plant cells made of cellulose, providing support.

Excretion

The elimination of metabolic waste products from an organism’s body.

Diabetes mellitus

Disease caused by hypo-secretion of insulin leading to high blood glucose.

Diabetes insipidus

Condition caused by hypo-secretion of antidiuretic hormone (ADH), resulting in excessive urination and thirst.

Pisum sativum

Scientific name of the garden pea used by Gregor Mendel in genetics experiments.

Hypotonic solution

Solution with lower solute concentration than a cell, causing endosmosis.

Hypertonic solution

Solution with higher solute concentration than a cell, causing exosmosis.

Abscisic acid (ABA)

Plant hormone that generally inhibits growth and promotes dormancy; antagonistic to auxins/gibberellins.

Auxin

Plant hormone promoting cell elongation and regulating phototropism and geotropism.

Thigmotropism

Growth movement of a plant in response to touch, e.g., tendrils of peas or ivy.

Non-biodegradable wastes

Materials that cannot be decomposed by microorganisms, persisting in the environment.

Swachh Bharat Abhiyan

Indian national campaign aiming to eliminate open defecation and improve sanitation and cleanliness.

Cranial nerves

Twelve pairs of nerves that emerge directly from the brain.

Spinal nerves

Thirty-one pairs of nerves that arise from the spinal cord.

Law of Dominance

Mendelian principle stating that one allele can mask the expression of another in a heterozygote.

ACTH

Adrenocorticotropic hormone; stimulates adrenal cortex to secrete corticosteroids.

ADH

Antidiuretic hormone; increases water reabsorption in kidneys and reduces urine volume.

Eustachian tube

Canal connecting the middle ear to the nasopharynx, equalising air pressure across the eardrum.

Natality

Birth rate; number of live births per 1000 individuals per year.

Sympathetic nervous system

Part of autonomic nervous system that generally increases heart rate and metabolic activity.

Parasympathetic nervous system

Part of autonomic nervous system that slows heart rate and promotes ‘rest-and-digest’ activities.

Glomerulus

Tuft of capillaries in the kidney’s renal corpuscle involved in filtration; located in the renal cortex.

Henle’s loop

U-shaped portion of nephron located in renal medulla; concentrates urine by creating osmotic gradient.

Ozone layer depletion

Reduction of stratospheric ozone leading to increased UV radiation, causing health and ecological damage.

Australopithecus

Early hominid genus characterised by upright posture, prognathous face, and absence of chin.

Identical (monozygotic) twins

Twins that develop from a single fertilised egg splitting into two embryos, sharing identical genetic makeup and always the same sex.

Phototropism

Directional growth of a plant shoot towards light, regulated by auxins.

Geotropism

Plant growth response to gravity; roots show positive geotropism by growing downward.

Vestibule (ear)

Central part of the bony labyrinth housing utricle and saccule; involved in balance.