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NEET UG · Biology · chapter
Human Physiology questions in NEET come to roughly eight to twelve of the ninety Biology questions, and most of them test a definition, a number or a sequence stated plainly in NCERT rather than anything you have to reason out. This guide gives the unit’s six chapters, the figures worth memorising, the five mistakes that cost the most marks, a free quiz and worked examples. BrainStride is an AI tutor for JEE, NEET and Olympiad preparation that runs a 20-minute diagnostic, maps your weak chapters and writes a daily plan, with every solution checked by teachers.
Quick answer
Questions per paper
8–12
Of 90 Biology questions · BrainStride analysis of past papers
Chapters in the unit
6
All Class 11, all in the Zoology half by convention
Question style
Recall + application
Definitions, numbers and sequences from NCERT
Marks at stake
Up to 48
At +4 each, before negative marking
BrainStride analysis of past papers
Respiratory organs and the mechanism of breathing, then the part NEET returns to every year: lung volumes and capacities by definition, and how oxygen and carbon dioxide are carried. Learn the four volumes and the capacities built from them as arithmetic, not as a list.
Blood and lymph, the human heart, the cardiac cycle and its 0.8-second timing, the ECG and double circulation. Questions usually ask which event a wave or a sound belongs to, or turn stroke volume and heart rate into cardiac output.
The nephron, urine formation and the counter-current mechanism. The high-value facts are quantitative: how much blood is filtered, how much filtrate forms, how much is reabsorbed and where each substance is reclaimed along the tubule.
Muscle structure and the sliding filament theory, then the skeleton and joints. The sliding filament question is nearly always about which bands change during contraction and which do not.
The neuron, resting and action potentials, impulse conduction and the synapse, then the central neural system and reflex action. Ion movements are the pinch point: which ion moves which way, and which pump maintains the resting state.
Endocrine glands, their hormones and the disorders of excess and deficiency. This is pure matching, and it is where a table beats paragraphs — gland, hormone, target, disorder, in four columns.
Statements to judge true or false, matching pairs, and single-step numericals on cardiac output or filtration. Almost nothing needs derivation, which is why an imprecise definition costs the same four marks as a concept you never studied.
CO = stroke volume × heart rate
About 70 mL × 72 per minute ≈ 5 L per minute in a healthy adult.
VC = IRV + TV + ERV
The maximum volume you can breathe out after a forced inspiration. Residual volume is not part of it.
TLC = VC + RV
Roughly 5,800 mL. Residual volume cannot be exhaled, so it appears only here.
IC = TV + IRV · FRC = ERV + RV
Both are built by addition — derive them rather than memorising four separate numbers.
≈97% by haemoglobin · ≈3% dissolved in plasma
Oxygen binds haemoglobin as oxyhaemoglobin; only a small fraction travels dissolved.
≈70% as bicarbonate · 20–25% as carbamino-haemoglobin · ≈7% dissolved
Carbonic anhydrase in red blood cells drives the bicarbonate route.
≈5 mL O₂ to tissues · ≈4 mL CO₂ to alveoli
At rest this works out to about 250 mL of oxygen delivered per minute.
GFR ≈ 125 mL per minute ≈ 180 L per day
The kidneys filter about 1,100–1,200 mL of blood per minute to produce it.
≈1.5 L per day from 180 L of filtrate
More than 99 per cent of the filtrate is reabsorbed — a favourite one-line question.
0.8 s per cycle at 72 beats per minute
P wave: atrial depolarisation. QRS: ventricular depolarisation. T wave: ventricular repolarisation.
≈ −70 mV · pump ratio 3 Na⁺ out : 2 K⁺ in
Depolarisation is sodium moving in; repolarisation is potassium moving out.
A band constant · I band and H zone shorten
The filaments slide; they do not contract. The sarcomere shortens because the overlap increases.
Why it happens
The four volumes are learnt as a list of numbers, so the capacities built from them get mixed up under time pressure.The fix
Write the four volumes once, then derive IC, EC, FRC, VC and TLC by addition. Check that residual volume appears in FRC and TLC but never in vital capacity.Why it happens
The cardiac cycle and the ECG are studied as two separate diagrams instead of one timeline.The fix
Draw the cycle and the trace on the same line: P before atrial systole, QRS at the start of ventricular systole, T at the end of it.Why it happens
Urine formation is remembered as three stages rather than as a route with a job at each segment.The fix
Walk the tubule in order and name what leaves at each point — proximal tubule for the bulk of water and electrolytes, loop for the concentration gradient, distal and collecting duct for fine control.Why it happens
The theory is recalled as "filaments slide", which answers no question actually set.The fix
Learn the three band changes as one sentence: A band unchanged, I band shortens, H zone narrows, so the sarcomere shortens.Why it happens
Hormones are revised gland by gland, but questions ask across glands — a hormone here, a disorder there.The fix
Keep one table with gland, hormone, target and the disorders of excess and deficiency, and revise it by column as well as by row.6 questions
Question 1
Which combination gives vital capacity?
Question 2
A person has a stroke volume of 70 mL and a heart rate of 72 beats per minute. What is the cardiac output?
Question 3
The QRS complex of an ECG represents:
Question 4
Most of the carbon dioxide in blood is transported as:
Question 5
During muscle contraction, which of these does NOT shorten?
Question 6
The glomerular filtration rate in a healthy adult is about:
A test on one chapter alone tells you little — the exam never asks Human Physiology in isolation. So this builds a full NEET Biology paper that leans on it. Weighted like the exam, a 90-question paper gives Human Physiology 14 questions; marked weak, it gets 24, and the rest of the paper keeps the other chapters honest. Fill the plan from previous-year questions or your module.
Your paper
Press Generate paper plan for a chapter-by-chapter blueprint: questions per chapter, numericals, marks and time — ready to print and fill from your PYQs, modules or the BrainStride question bank.
Chapter weights are BrainStride’s reading of past papers, not official data. For any other chapter mix, use the NEET Biology test generator.
Single-step numerical · body fluids
A person has a stroke volume of 80 mL and a heart rate of 75 beats per minute. How many times does a blood volume of 5 litres circulate through the heart in one minute?
Answer: The whole blood volume passes through the heart about 1.2 times every minute.
Assertion and reason · breathing
Assertion: subtracting the expiratory reserve volume from vital capacity leaves the inspiratory capacity. Reason: inspiratory capacity is tidal volume plus inspiratory reserve volume.
Answer: Both statements are true, and the reason is the correct explanation — the subtraction works precisely because IC is defined as TV + IRV.
Two-step numerical · gas transport
Every 100 mL of oxygenated blood delivers about 5 mL of oxygen to the tissues. At a cardiac output of 5 litres per minute, how much oxygen reaches the tissues each minute?
Answer: About 250 mL of oxygen is delivered to the tissues per minute, the figure NCERT quotes for a resting adult.
In recent NEET papers, Human Physiology has carried roughly 8 to 12 of the 90 Biology questions. That is BrainStride’s analysis of past papers, not an official figure — NTA publishes no chapter-wise weightage for NEET UG. Treat it as a reason to finish the unit early, not as a promise about any one paper.
The current NEET syllabus lists six chapters in this unit: Breathing and Exchange of Gases, Body Fluids and Circulation, Excretory Products and their Elimination, Locomotion and Movement, Neural Control and Coordination, and Chemical Coordination and Integration. Confirm the unit against the official syllabus on neet.nta.nic.in before you plan around it.
For this unit, largely yes. Most questions test a definition, a number or a sequence stated in NCERT, so the work is reading it closely rather than reading more books. What NCERT will not give you is repetition under time — that comes from previous-year questions and timed practice on the same six chapters.
Body fluids and circulation, because it mixes definitions with a timeline. Students can recite the cardiac cycle and still match the QRS complex to the wrong event, or know stroke volume without converting it to cardiac output. Practising the cycle, the ECG and the numbers together fixes most of the loss.
Revise by table rather than by chapter: one table of lung volumes and capacities, one of cardiac cycle events against ECG waves, one of nephron segments against what each reabsorbs, and one of glands, hormones and disorders. Then attempt mixed questions across all six chapters, because that is how the paper asks them.
It supports it. Human Physiology is Class 11, but Human Reproduction, Human Health and Disease, and parts of Biotechnology assume you already know circulation, excretion and hormonal control. Students who leave this unit for the end usually end up revising it twice anyway, so it is cheaper to finish it first.
The 20-minute diagnostic checks Human Physiology against the rest of Biology and names the two units to fix first. Free, no card.