25 questions in 25 minutes on the NTA computer-based test interface, all from Body Fluids and Circulation. +4 / -1 marking, instant score, full solutions. Free, no login.
A chapter test is the fastest honest check on whether a chapter has actually landed. This one draws 25 questions from Body Fluids and Circulation, of which 17 are real NEET previous-year questions and 6 sit at the harder end of the bank. Sit it in one 25-minute block, the way you would in the hall.
Revising first? Read the Body Fluids and Circulation chapter notes, then come back and take this test to check it stuck.
Loading your test…
Fetching the question paper. This takes a moment on a slow connection.
This test is part of the paid library
Unlock all 72 timed NEET CBT papers once, keep them forever. The 30 chapter tests stay free.
One payment. No subscription. Works on any device you log the key into.
Already bought it?
Paste the licence key from your payment email.
Duration: 180 minutes · 180 questions · 720 marks maximum
- The clock will be set at the server. The countdown timer at the top right of the screen will display the remaining time. When the timer reaches zero, the examination will end by itself.
- The Question Palette displayed on the right side of the screen will show the status of each question using one of the following symbols:
- Each correct answer carries +4 marks; each incorrect answer carries −1 mark. Un-attempted questions carry no marks.
- Navigate between sections using the section tabs, and between questions using SAVE & NEXT or the Question Palette.
- Your answers are saved in this browser, so an accidental refresh will not wipe a test in progress.
Submit the test?
Once you submit you cannot change answers. You will see your score and full solutions.
Your Result
Practice another mock test → · Continue practising on the ChapterNotes app →
Solutions & Revision
More Zoology chapter tests
All NEET Zoology CBT tests · The full NEET 2027 CBT mock library
NEET CBT mock test: common questions
How many questions are in this Body Fluids and Circulation mock test?
25 questions in 25 minutes, marked +4 for a correct answer and -1 for a wrong one, exactly like the real paper. 17 of them are NEET previous-year questions.
Is this the same interface as the real NEET CBT?
Yes. On-screen countdown, colour-coded question palette, Save & Next, Clear Response and Mark for Review, then an instant score with full solutions.
Should I take this before or after revising Body Fluids and Circulation?
Both, and that is the point. Take it cold to find out what you actually do not know, revise from the chapter notes, then retake it to confirm the gap closed.
All 25 questions with answers and solutions
The complete paper in text form, with the correct option and a worked explanation for every question. Sit the timed test above first: the score is only worth having if you earn it. Then open this to revise, or to re-read a question you got wrong without replaying the whole paper.
Show all 25 questions with answers and solutions
Zoology
- Q1The ‘dup’ (second heart) sound is produced during the closure of:
- Tricuspid valve
- Both bicuspid and tricuspid valves
- Semilunar valves
- Bicuspid valve
Answer: (C) Semilunar valves
During joint diastole the rapid closure of the semilunar valves produces the second heart sound (‘dup’). The first sound (‘lub’) is produced by closure of the AV (bicuspid + tricuspid) valves at the start of ventricular systole.
- Q2RBCs do NOT occur in:
- Camel
- Cow
- Frog
- Cockroach
Answer: (D) Cockroach
RBCs (carrying respiratory pigment for gas transport) occur in vertebrates such as frog, cow and camel. In the cockroach, the haemolymph lacks RBCs – its respiratory pigment is absent and gases are carried by the tracheal system, not blood. Hence cockroach.
- Q3In a normal ECG, the QRS complex represents:
- Atrial depolarisation
- Atrial repolarisation
- Ventricular repolarisation
- Ventricular depolarisation
Answer: (D) Ventricular depolarisation
The QRS complex represents depolarisation of the ventricles, which initiates their contraction. The P wave is atrial depolarisation and the T wave is ventricular repolarisation.
- Q4A closed circulatory system occurs in:
- Mosquito
- Cockroach
- House fly
- Tadpole/fish
Answer: (D) Tadpole/fish
In a closed circulatory system, blood flows in closed vessels (arteries, veins, capillaries) – found in annelids, cephalopods and all vertebrates including frog/fish (tadpole). Insects (cockroach, mosquito, housefly) have an open circulatory system. Hence tadpole/fish.
- Q5A person with blood group A requires blood. The blood group(s) which can be given to him is/are:
- A and B
- A and O
- A, B, AB and O
- A and AB
Answer: (B) A and O
A group-A recipient has anti-B antibodies in plasma, so donor cells must carry no B antigen. Group A (A antigen, fine) and group O (no antigen, fine) are safe; B and AB carry the B antigen and would be agglutinated. Hence A and O.
- Q6If due to some injury the chordae tendineae of the tricuspid valve of the human heart is partially non-functional, what will be the immediate effect?
- The flow of blood into the pulmonary artery will be reduced
- The ‘pacemaker’ will stop working
- The flow of blood into the aorta will be slowed down
- The blood will tend to flow back into the left atrium
Answer: (A) The flow of blood into the pulmonary artery will be reduced
Chordae tendineae anchor the tricuspid valve (right side) so it allows one-way flow from right atrium to right ventricle. If they fail, blood leaks back into the right atrium during ventricular systole, so less blood is pumped from the right ventricle into the pulmonary artery. (It cannot affect the left atrium, which involves the bicuspid valve.) Hence D.
- Q7Which of the following is NOT a main function of lymph glands (nodes)?
- Destroying bacteria
- Forming WBC
- Forming antibodies
- Forming RBC
Answer: (D) Forming RBC
Lymph nodes produce lymphocytes (WBCs), synthesise antibodies and destroy bacteria by phagocytosis. They do NOT form RBCs (erythropoiesis occurs in red bone marrow). Hence forming RBC is not a function of lymph glands.
- Q8Antibodies in our body are complex:
- Prostaglandins
- Lipoproteins
- Steroids
- Glycoproteins
Answer: (D) Glycoproteins
Antibodies (immunoglobulins) are glycoproteins produced by B-lymphocytes/plasma cells in response to an antigen. They are not lipoproteins, steroids or prostaglandins.
- Q9The pacemaker of the heart is the:
- Bundle of His
- AV node
- SA node
- Purkinje fibres
Answer: (C) SA node
The SA node, in the right atrial wall near the opening of the superior vena cava, is the first to originate the cardiac impulse and sets the heart rate, so it is the pacemaker.
- Q10A specialised nodal tissue embedded in the lower corner of the right atrium, close to the atrio-ventricular septum, delays the spreading of impulses to the heart apex. This delay allows:
- The atria to empty completely
- Blood to enter the aorta
- Blood to enter the pulmonary arteries
- The ventricles to empty completely
Answer: (A) The atria to empty completely
The structure described is the AV node, which delays the impulse by ~0.1 s. This pause allows the atria to finish contracting and empty completely into the ventricles before the ventricles contract. Hence D.
- Q11All the components of the nodal tissue are autoexcitable. Why does the SA node act as the normal pacemaker?
- SA node has the lowest rate of depolarisation
- SA node is the only component to generate the threshold potential
- Only the SA node can convey the action potential to the other components
- SA node has the highest rate of depolarisation
Answer: (D) SA node has the highest rate of depolarisation
Although all nodal tissue is autoexcitable, the SA node depolarises at the highest rate (~70-75/min), so it fires first and sets the rhythm before slower components (AV node etc.) reach threshold. Therefore the SA node is the pacemaker.
- Q12The milky lymph rich in absorbed fats present in the lacteals of intestinal villi is called:
- Plasma
- Chyle
- Bile
- Serum
Answer: (B) Chyle
Absorbed fats enter the lacteals (lymph capillaries) of the villi, forming a milky fluid called chyle. This is how fats are absorbed via the lymphatic route.
- Q13Vitamin K is required for:
- Synthesis of prothrombin
- Conversion of fibrinogen to fibrin
- Formation of thromboplastin
- Conversion of prothrombin to thrombin
Answer: (A) Synthesis of prothrombin
Vitamin K (phylloquinone) is required by the liver for the synthesis of prothrombin, the precursor needed for blood clotting. It does not itself form thromboplastin or directly convert fibrinogen/prothrombin – those are enzymatic steps. Hence D.
- Q14Pulmonary artery is different from pulmonary vein because it has:
- No endothelium
- Thick muscular walls
- Valves
- Larger lumen
Answer: (B) Thick muscular walls
Arteries, including the pulmonary artery, have thick muscular walls and a narrow lumen (to withstand high pressure) and no valves, whereas veins have thinner walls, a larger lumen and valves. Endothelium is present in both. Hence the pulmonary artery has thick muscular walls.
- Q15What would be the heart rate of a person if the cardiac output is 5 L, the blood volume in the ventricles at the end of diastole is 100 mL and at the end of ventricular systole is 50 mL?
- 125 beats per minute
- 50 beats per minute
- 100 beats per minute
- 75 beats per minute
Answer: (C) 100 beats per minute
Stroke volume = end-diastolic volume − end-systolic volume = 100 − 50 = 50 mL. Cardiac output = stroke volume × heart rate, so 5000 mL/min = 50 mL × heart rate → heart rate = 100 beats/min.
- Q16The fact that the heartbeat is initiated by the SA node within the heart muscle itself means the human heart is:
- Aneurogenic
- Neurogenic
- Myogenic
- Chlorogenic
Answer: (C) Myogenic
Because the impulse for contraction arises from specialised muscle tissue (SA node) rather than from nerves, the human heart is described as myogenic. Nerves only modulate the rate.
- Q17Assertion (A): Lymph helps in the transport of nutrients and oxygen between blood and tissue cells. Reason (R): Lymph is the interstitial fluid that bathes the body cells and exchanges substances with capillaries.
- Both A and R are true but R is not the correct explanation of A
- A is false but R is true
- A is true but R is false
- Both A and R are true and R is the correct explanation of A
Answer: (D) Both A and R are true and R is the correct explanation of A
Lymph is the tissue fluid filling intercellular spaces; because it bathes the cells, it serves as the exchange medium that carries nutrients/O₂ to cells and wastes back to blood. R correctly explains A.
- Q18In a standard ECG, the P-wave represents the:
- Initiation of ventricular contraction
- Beginning of the systole
- Contraction of both the atria
- End of systole
Answer: (C) Contraction of both the atria
The P-wave represents depolarisation of the atria, which leads to contraction of both atria. The QRS marks ventricular depolarisation/contraction, and the T-wave the end of ventricular systole (repolarisation). Hence A.
- Q19The life span of a human WBC (leucocyte) is approximately:
- Between 2-3 months
- Less than 10 days
- Between 20-30 days
- More than 4 months
Answer: (B) Less than 10 days
Human leucocytes are short-lived, with a life span of less than about 10 days (often only a few days). RBCs, by contrast, live ~120 days. Hence option A.
- Q20A vein possesses a large lumen because:
- Tunica media is a thin coat
- Tunica interna and tunica media form a single coat
- Tunica interna, tunica media and tunica externa are thin
- Tunica media and tunica externa form a single coat
Answer: (A) Tunica media is a thin coat
A vein has the same three layers (tunica interna, media, externa) as an artery, but its tunica media (smooth muscle/elastic layer) is comparatively thin. This thin muscular coat gives veins a relatively large lumen. Hence D.
- Q21If the stroke volume is 70 mL and the heart rate is 72 beats per minute, the cardiac output is approximately:
- 5 L/min
- 1 L/min
- 10 L/min
- 0.5 L/min
Answer: (A) 5 L/min
Cardiac output = stroke volume × heart rate = 70 mL × 72 = 5040 mL/min ≈ 5 L/min.
- Q22During the joint diastole phase of the cardiac cycle:
- Semilunar valves are open
- The tricuspid and bicuspid valves are closed
- Only the ventricles contract
- All four chambers are in relaxed state and chambers refill with blood
Answer: (D) All four chambers are in relaxed state and chambers refill with blood
In joint diastole all chambers relax; semilunar valves close (producing the second sound) and the AV valves open so blood flows from atria/veins into the ventricles, refilling them.
- Q23At a heart rate of 75 beats per minute, the duration of one cardiac cycle is approximately:
- 0.4 s
- 1.0 s
- 0.8 s
- 0.6 s
Answer: (C) 0.8 s
Duration of one cycle = 60 s ÷ heart rate = 60 ÷ 75 = 0.8 s. (The standard textbook value at 72-75 bpm is ~0.8 s.)
- Q24Which of the following conditions causes erythroblastosis foetalis?
- Mother Rh+ve and foetus Rh-ve
- Both mother and foetus Rh+ve
- Both mother and foetus Rh-ve
- Mother Rh-ve and foetus Rh+ve
Answer: (D) Mother Rh-ve and foetus Rh+ve
Erythroblastosis foetalis occurs when an Rh-ve mother carries an Rh+ve foetus. Anti-Rh antibodies formed by the mother (after sensitisation) cross the placenta in a subsequent Rh+ pregnancy and destroy the foetal RBCs.
- Q25Which valve guards the opening between the left atrium and the left ventricle?
- Bicuspid (mitral) valve
- Tricuspid valve
- Pulmonary semilunar valve
- Aortic semilunar valve
Answer: (A) Bicuspid (mitral) valve
The bicuspid (mitral) valve lies between the left atrium and left ventricle. The tricuspid valve is on the right side; semilunar valves guard the bases of the aorta and pulmonary artery.