General Science (with emphasis on Biology and Health)
General Science here is weighted towards human biology, microbes and public-health-relevant chemistry. Expect questions on the cell, blood, nutrition, hormones, immunity and the biology of the parasites you will actually be fighting.
Core syllabus
- Cell and tissues: mitochondria for energy, ribosomes for protein synthesis, prokaryote versus eukaryote.
- Human systems: circulatory (blood groups, haemoglobin, clotting), respiratory, digestive, excretory, nervous and endocrine.
- Nutrition and deficiency: vitamin A and night blindness, B1 and beriberi, C and scurvy, D and rickets, iron and anaemia, iodine and goitre.
- Microbes and immunity: bacteria, viruses, protozoa, helminths; active versus passive immunity; live versus killed vaccines.
- Applied chemistry: water hardness, chlorine as a disinfectant, bleaching powder strength.
Worked example
Why does Plasmodium vivax malaria relapse, and what prevents it? Reasoning: P. vivax produces hypnozoites - dormant liver-stage forms that are not affected by blood schizontocides. Chloroquine clears the blood stages and ends the acute attack, but weeks later hypnozoites reactivate and cause relapse. Primaquine is the hypnozoitocide used for radical cure (14 days in India). Because primaquine can cause haemolysis in G6PD deficiency, G6PD status should be considered before the long course. P. falciparum has no hypnozoite stage, so it does not relapse in this way.
Traps that cost marks
- Calling malaria a viral disease, or naming Aedes as its vector.
- Confusing active immunity (body makes antibodies, as after vaccination or infection) with passive immunity (antibodies given, as in breast milk or antiserum).
- Mixing up deficiency diseases under exam pressure.
- Forgetting that only the female Anopheles mosquito transmits malaria.