ICSE Class 10 Biology Syllabus

What is the functional unit of the kidney called and what is its role?

The nephron; it filters blood and forms urine through ultrafiltration, selective reabsorption, and tubular secretion.

Name the parts of a neuron.

Cell body (cyton), dendrites, axon, and nerve endings (axon terminals); the axon may be covered by a myelin sheath.

Differentiate between a reflex action and a voluntary action.

A reflex action is an automatic, involuntary, rapid response to a stimulus controlled by the spinal cord; a voluntary action is a deliberate response controlled by the brain (cerebrum).

Name the endocrine gland called the 'master gland' and one hormone it secretes.

The pituitary gland; it secretes growth hormone (also TSH, ACTH, FSH, LH, etc.).

Differentiate between asexual and sexual reproduction.

Asexual reproduction involves a single parent and produces genetically identical offspring without gametes; sexual reproduction involves two parents and fusion of gametes, producing genetically varied offspring.

What is fertilisation?

Fertilisation is the fusion of the male gamete (sperm) with the female gamete (egg/ovum) to form a zygote.

Name the male and female reproductive organs of a flower.

Male: stamen (anther and filament). Female: carpel/pistil (stigma, style, and ovary).

Differentiate between self-pollination and cross-pollination.

Self-pollination is the transfer of pollen from the anther to the stigma of the same flower (or another flower on the same plant); cross-pollination is the transfer of pollen to the stigma of a flower on a different plant of the same species.

State Mendel's Law of Segregation.

The two alleles of a gene (factors for a trait) separate during gamete formation, so each gamete receives only one allele of each pair.

State Mendel's Law of Independent Assortment.

During gamete formation, the alleles of one gene assort (segregate) independently of the alleles of another gene.

Differentiate between genotype and phenotype.

Genotype is the genetic constitution (allele combination, e.g. Tt) of an organism; phenotype is its observable physical expression (e.g. tall).

In a monohybrid cross between two heterozygous tall pea plants (Tt x Tt), what is the phenotypic and genotypic ratio of the F2 generation?

Phenotypic ratio 3 tall : 1 dwarf; genotypic ratio 1 TT : 2 Tt : 1 tt.

How is the sex of a human child determined?

The mother contributes only an X chromosome; the father contributes either X or Y. An XX combination gives a girl and an XY combination gives a boy, so the father determines the sex.

Differentiate between mitosis and meiosis.

Mitosis produces two genetically identical diploid cells for growth and repair; meiosis produces four genetically varied haploid cells (gametes) and reduces the chromosome number by half.

Define an ecosystem.

An ecosystem is a self-sustaining unit in which living organisms (biotic components) interact with one another and with their non-living physical environment (abiotic components).

Differentiate between biotic and abiotic components of an ecosystem.

Biotic components are the living organisms (producers, consumers, decomposers); abiotic components are the non-living factors such as light, temperature, water, soil, and air.

What is a food chain? Give an example.

A food chain is the sequence of organisms through which energy and nutrients pass as one organism feeds on another, e.g. grass -> grasshopper -> frog -> snake -> hawk.

Differentiate between producers, consumers, and decomposers.

Producers (green plants) make their own food by photosynthesis; consumers eat other organisms; decomposers (bacteria, fungi) break down dead organic matter and recycle nutrients.

What is the 10% law of energy flow in an ecosystem?

Only about 10% of the energy at one trophic level is transferred to the next trophic level; the remaining 90% is lost mainly as heat during respiration and life activities.

Why does energy flow in an ecosystem always remain unidirectional?

Because energy enters as sunlight, flows from producers to consumers, and is lost as heat at each level; it cannot be reused or flow back, so it moves in one direction only.

Name two greenhouse gases and the environmental effect they cause.

Carbon dioxide and methane (also water vapour, CFCs); they trap heat in the atmosphere, causing the greenhouse effect and global warming.

What is biodegradable waste? Give one example.

Biodegradable waste is waste that can be broken down (decomposed) by microorganisms into harmless substances, e.g. food scraps, paper, or cow dung.

Differentiate between a communicable and a non-communicable disease.

A communicable (infectious) disease spreads from an infected person to a healthy person (e.g. tuberculosis); a non-communicable disease does not spread and is caused by lifestyle, deficiency, or genetics (e.g. diabetes).

Name the causative organism and main symptom of malaria.

Caused by the protozoan Plasmodium (transmitted by the female Anopheles mosquito); main symptom is recurring high fever with chills.

Which mosquito transmits dengue, and what is the disease type?

The Aedes aegypti mosquito transmits dengue, which is a viral disease.

Define immunity and name its two main types.

Immunity is the ability of the body to resist or fight off pathogens. Two types: innate (natural/inborn) immunity and acquired (adaptive) immunity.

What is a vaccine and how does it work?

A vaccine is a preparation of weakened or dead pathogens (or their antigens) introduced into the body; it stimulates the immune system to produce antibodies and memory cells, giving active immunity against that disease.

Name the deficiency disease caused by lack of Vitamin C and its symptom.

Scurvy; symptoms include bleeding and swollen gums.

Name the disease caused by deficiency of Vitamin D and its effect in children.

Rickets; it causes soft, weak, and deformed (bent) bones in children.

State two ways to break the transmission of water-borne diseases like cholera.

Drinking boiled or properly purified water and maintaining good sanitation/hygiene (proper sewage disposal and washing hands).