NDA Examination General Science and Biology (General Ability Test) Syllabus

What hormone regulates blood sugar and which organ secretes it?

Insulin, secreted by the beta cells of the islets of Langerhans in the pancreas; it lowers blood glucose.

What are the main parts of the human nervous system?

Central Nervous System (brain and spinal cord) and Peripheral Nervous System (nerves). The functional unit is the neuron.

Which pathogen causes Malaria and how is it transmitted?

The protozoan Plasmodium, transmitted by the bite of the female Anopheles mosquito.

Name the causative agent and mode of spread of Tuberculosis (TB).

Caused by the bacterium Mycobacterium tuberculosis; spreads through air (droplets from coughing/sneezing) and affects mainly the lungs.

What type of pathogen causes AIDS, and what does HIV target?

AIDS is caused by HIV (Human Immunodeficiency Virus), which attacks and weakens the immune system (specifically CD4/helper T-cells).

Give two examples each of bacterial and viral diseases in humans.

Bacterial: Tuberculosis, Cholera, Typhoid, Tetanus. Viral: Influenza, Dengue, Polio, COVID-19, Measles.

What is a vaccine and on what principle does it work?

A vaccine is a preparation of weakened/killed pathogens or their antigens that stimulates the immune system to produce antibodies, giving immunity. It works on the principle of acquired (active) immunity. Edward Jenner pioneered vaccination (smallpox).

Which deficiency disease is caused by lack of Vitamin C and what are its symptoms?

Scurvy; symptoms include bleeding/swollen gums, weakness, and slow wound healing. Vitamin C is ascorbic acid.

What disease results from Vitamin D deficiency and what is its main function?

Rickets (in children) and osteomalacia (in adults). Vitamin D aids absorption of calcium and phosphorus for strong bones.

Which vitamin deficiency causes night blindness and what is the vitamin's chemical name?

Vitamin A (retinol) deficiency causes night blindness; it is needed for healthy vision and skin.

What deficiency causes Beri-beri and which vitamin is responsible?

Beri-beri is caused by deficiency of Vitamin B1 (Thiamine), affecting the nervous and cardiovascular systems.

Which mineral deficiency causes goitre, and which gland is affected?

Iodine deficiency causes goitre (enlargement of the thyroid gland), as iodine is needed to make thyroid hormones.

What is the difference between asexual and sexual reproduction?

Asexual reproduction involves a single parent and produces genetically identical offspring (no gametes); sexual reproduction involves two parents and gametes, producing genetically varied offspring.

Name three methods of asexual reproduction in plants/organisms.

Binary fission (Amoeba), budding (Hydra, yeast), fragmentation (Spirogyra), spore formation (fungi), and vegetative propagation (potato, ginger).

What is pollination and what are its two types?

Pollination is the transfer of pollen from anther to stigma. Self-pollination (same flower/plant) and cross-pollination (between different plants).

What are the male and female reproductive parts of a flower?

Male part: Stamen (anther + filament). Female part: Pistil/Carpel (stigma + style + ovary).

In humans, where does fertilization occur and where does the embryo develop?

Fertilization occurs in the fallopian tube (oviduct); the embryo develops in the uterus (womb).

Who is known as the 'Father of Genetics' and what organism did he study?

Gregor Mendel; he studied inheritance in pea plants (Pisum sativum) and formulated the laws of inheritance.

State Mendel's Law of Segregation.

During gamete formation, the two alleles of a gene separate (segregate) so that each gamete carries only one allele for each trait.

How many chromosomes are present in a normal human body cell?

46 chromosomes (23 pairs), including one pair of sex chromosomes (XX in females, XY in males).

What determines the sex of a child in humans, and how?

The father's sperm determines sex: an X-carrying sperm gives a girl (XX), a Y-carrying sperm gives a boy (XY). The mother always contributes an X.

What is the difference between genotype and phenotype?

Genotype is the genetic makeup (set of alleles, e.g., Tt); phenotype is the observable physical characteristic (e.g., tall plant).

Who proposed the Theory of Evolution by Natural Selection?

Charles Darwin, in his book 'On the Origin of Species' (1859). His theory is summarized as 'survival of the fittest'.

What is Lamarck's theory of evolution called?

The theory of 'Inheritance of Acquired Characters' (use and disuse of organs), proposed by Jean-Baptiste Lamarck.

Name three great scientists and their major contributions.

Isaac Newton - laws of motion and gravitation; Albert Einstein - theory of relativity (E=mc²); C.V. Raman - Raman effect (Nobel Prize 1930).

Which Indian scientist is credited with discovering that plants have life and feelings, and what device did he invent?

Jagadish Chandra Bose; he invented the crescograph to measure plant growth and responses.

Name the eight planets of the Solar System in order from the Sun.

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. (Pluto is now a dwarf planet.)

Which is the largest planet and which is the smallest planet in the Solar System?

Largest planet: Jupiter; Smallest planet: Mercury.

What is a light year and is it a unit of distance or time?

A light year is the distance light travels in one year (about 9.46 trillion km); it is a unit of distance, not time.

What was India's first satellite and which organization launched the Mars Orbiter Mission (Mangalyaan)?

India's first satellite was Aryabhata (1975). The Mars Orbiter Mission (Mangalyaan, 2013) was launched by ISRO, making India the first country to reach Mars orbit on its first attempt.

Name a recent Indian space and a defence missile achievement.

Chandrayaan-3 (2023) achieved a soft landing near the Moon's south pole; Agni and BrahMos are key indigenous missiles. BrahMos is a supersonic cruise missile developed jointly by India and Russia.