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Playbook

Human Physiology

52 q · 2% HARD — the largest chapter. Circulatory + Lymphatic (13 q · RBC/WBC/blood groups), Digestive + Enzymes (7 · 14% HARD), Nutrition + Vitamins + Minerals (7 · vitamin↔deficiency table), plus nervous/endocrine/respiratory/tissues. Pure named-fact recall — drill /reference-tables → 'Vitamins' and 'Hormones' clusters side-by-side.

questions in the bank
52
tagged HARD
2%
subtopic(s)
9
worked examples
2

When you’ll see it

A blood-component or blood-group identification, a digestive-enzyme match (pepsin/trypsin/amylase), a vitamin↔deficiency-disease pair, an endocrine-gland↔hormone match, a respiratory-process question, or a sense-organ function.

How this chapter is tested

52 q in 10 years — NDA Biology's largest chapter. 1 HARD across the whole window, so it's mostly pure recall. The Circulatory + Lymphatic subtopic alone is 13 q: RBC (no nucleus, biconcave, lifespan ~120 days, carries O₂ via haemoglobin), WBC (5 types — neutrophils, lymphocytes, monocytes, eosinophils, basophils), platelets (clotting), 4 blood groups (A, B, AB, O — universal donor O, universal recipient AB), and the lymphatic system (collects tissue fluid, returns to blood via thoracic duct).

Digestive System + Enzymes (7 q, 14% HARD) is the chapter's lone trap pocket. Memorise the enzyme table: salivary amylase (mouth, starch → maltose), pepsin (stomach, acid-activated, protein → peptides), trypsin (small intestine, pancreatic, protein → amino acids), lipase (small intestine, fat → fatty acids + glycerol). The acid-secreting cells of the stomach wall produce HCl, which activates pepsinogen → pepsin — damage these cells and PROTEIN digestion suffers most (HARD 2018 PYQ).

Nutrition + Vitamins + Minerals (7 q) is the named-fact recall workhorse. Vitamin C deficiency = scurvy. Vitamin D deficiency = rickets (children) / osteomalacia (adults). Vitamin A deficiency = night blindness. Vitamin B1 (thiamine) deficiency = beriberi. Vitamin K = blood clotting. Intestinal bacteria synthesise vitamin K + some B vitamins. Drill /reference-tables → 'Vitamins and Deficiencies' cluster. The Endocrine subtopic (5 q) tests gland↔hormone pairs — pituitary (master gland), thyroid (thyroxine, regulates metabolism), adrenal (adrenaline, fight-or-flight), pancreas (insulin/glucagon, glucose regulation).

The sub-skills

The rules and habits that decide whether you get a question right.

  • Blood-component property recall

    RBC: NO nucleus (in mammals), biconcave, ~120-day lifespan, contains haemoglobin (O₂ + CO₂ transport). WBC: HAS nucleus, 5 types (lymphocytes = adaptive immunity / neutrophils = bacterial phagocytosis). Platelets: cell fragments, clotting. Plasma: 90% water, transports nutrients/wastes/hormones.

  • Digestive enzyme match

    Salivary amylase (mouth, pH 7) → starch to maltose. Pepsin (stomach, pH 1.5–2 — needs HCl) → protein to peptides. Trypsin + chymotrypsin (small intestine, pancreatic) → peptides to amino acids. Lipase (small intestine, pancreatic + bile-emulsified) → fats to fatty acids + glycerol. Bile = NOT enzyme (just emulsifier).

  • Vitamin–deficiency pair recall

    A → night blindness. B1 (thiamine) → beriberi. B2 → cracks at mouth corners. B3 (niacin) → pellagra. B12 → pernicious anaemia. C (ascorbic) → scurvy. D → rickets / osteomalacia. E → reproductive issues + neuropathy. K → bleeding (no clotting). Drill the table.

  • Hormone–gland pair recall

    Pituitary (master) → GH, FSH, LH, TSH, ACTH, prolactin, ADH, oxytocin. Thyroid → thyroxine (T4) + calcitonin. Parathyroid → PTH (calcium homeostasis). Adrenal → adrenaline, noradrenaline, cortisol, aldosterone. Pancreas → insulin (β-cells) + glucagon (α-cells). Ovaries → estrogen + progesterone. Testes → testosterone.

2 worked examples from the bank

Real past-year questions illustrating the playbook. Click to reveal options + solution.

Example 1Human PhysiologyHARD
If by an unknown accident the acid secreting cells of the stomach wall of an individual are damaged, digestion of which one of the following biomolecule will be affected to a greater extent?

[Q93 · Apr · 2018]

Example 2Human PhysiologyEASY
In which cell does the first meiotic cell division take place during spermatogenesis?

[Q94 · Apr · 2026]

Traps to expect

Distractor shapes specific to this chapter. The page-wide Traps section covers the bank-level patterns.

  • RBC has nucleus (in mammals)

    Mammalian RBCs LOSE their nucleus during maturation — that's why they're biconcave (max surface area for O₂ uptake) and have a ~120-day lifespan. Distractor says 'mature RBCs have a nucleus' or 'RBCs synthesise haemoglobin throughout life'. Frog/bird RBCs DO have nuclei, but NDA uses 'human' or 'mammal' context.

  • Universal donor vs recipient swap

    O = universal DONOR (no A/B antigens to attack). AB = universal RECIPIENT (no A/B antibodies to react). Distractor swaps them — 'AB is universal donor' or 'O is universal recipient'. The donor rule is about ANTIGENS on RBCs; the recipient rule is about ANTIBODIES in plasma.

  • Pepsin works in alkaline conditions

    Pepsin is ACTIVATED by HCl (stomach pH ~1.5–2). It DENATURES in alkaline pH (small intestine pH ~8 — that's why trypsin takes over there). Distractor says pepsin works best at neutral or alkaline pH. Mnemonic: 'pepsin = acidic stomach, trypsin = alkaline small intestine'.

Drill every human physiology question

52 questions from the bank, scoped to 9 bundled subtopics.

Drill the 52 questions

Related playbooks

Often paired with this one — drill these next if you found the worked examples above tractable.