Practice tests · NEET

NEET Body Fluids and Circulation: 5 practice MCQs

By the PrepMatic team · Updated 9 Oct 2026 · 3 min read

Body Fluids and Circulation covers blood, lymph and the working of the human heart, and it is one of the more predictable Class 11 Biology chapters. The five MCQs below test the universal recipient, the heart sounds, cardiac output, the pacemaker of the heart and what the QRS complex shows in an ECG.

What this chapter covers in the NEET syllabus

This chapter belongs to the NMC unit Human Physiology and is the Class 11 NCERT chapter Body Fluids and Circulation. The topics are:

• Blood: plasma and formed elements (RBCs, WBCs, platelets), blood groups (ABO and Rh) and coagulation.
• Lymph and the lymphatic system.
• The human circulatory system: the structure of the heart and blood vessels.
• The cardiac cycle, heart sounds and cardiac output.
• The electrocardiogram (ECG), double circulation and regulation of cardiac activity.
• Disorders of the circulatory system: hypertension, coronary artery disease and heart failure.

Five practice MCQs on Body Fluids and Circulation

Question 1

Which blood group is called the universal recipient?

• A. O
• B. A
• C. B
• D. AB

Question 2

The second heart sound, "dub", is produced by the closure of the:

• A. tricuspid and bicuspid valves
• B. semilunar valves
• C. coronary valves
• D. valves of the veins

Question 3

A person has a heart rate of 72 beats per minute and a stroke volume of 70 mL. The cardiac output is about:

• A. 5040 mL per minute
• B. 2520 mL per minute
• C. 10080 mL per minute
• D. 720 mL per minute

Question 4

The pacemaker of the human heart is the:

• A. Purkinje fibres
• B. atrioventricular node
• C. bundle of His
• D. sinoatrial node

Question 5

In an ECG, the QRS complex represents:

• A. ventricular depolarisation
• B. atrial depolarisation
• C. ventricular repolarisation
• D. the return of the atria to normal

Answers and explanations

1. D. Blood group AB has both antigens A and B on RBCs but no antibodies in plasma, so it can receive blood from any ABO group. Group O has no antigens and is the universal donor.
2. B. The first sound, "lub", comes from the closure of the tricuspid and bicuspid valves at the start of ventricular systole. The second sound, "dub", comes from the closure of the semilunar valves at the start of ventricular diastole.
3. A. Cardiac output is heart rate × stroke volume = 72 × 70 = 5040 mL per minute, about 5 litres, which matches the value given for a healthy adult in NCERT.
4. D. The sinoatrial node, in the upper right atrium, generates the impulses that start each cardiac cycle (about 70 to 75 times per minute), so it is the pacemaker. The AV node passes the impulse to the bundle of His and the Purkinje fibres.
5. A. The P wave shows atrial depolarisation, the QRS complex shows ventricular depolarisation (which starts ventricular contraction), and the T wave shows the return of the ventricles to normal (repolarisation). Atrial repolarisation is hidden within the QRS complex.

How to prepare Body Fluids and Circulation

• Learn the blood group table once and use it for everything. Antigens on RBCs and antibodies in plasma for A, B, AB and O, who can donate to whom, and the Rh system with erythroblastosis foetalis, which occurs when an Rh-negative mother carries an Rh-positive foetus.
• Memorise the cardiac cycle in order. Atrial systole, ventricular systole, joint diastole, with valve opening and closing, and the sounds that follow each step. Know the duration (0.8 s per cycle) and the numbers for stroke volume, heart rate and cardiac output.
• Draw the human heart and mark the valves (tricuspid on the right, bicuspid or mitral on the left), the vessels and the direction of flow. Add the nodal tissue (SAN, AVN, bundle of His, Purkinje fibres).
• Understand double circulation: pulmonary circuit versus systemic circuit, and the portal systems (hepatic portal vein). Compare arteries, veins and capillaries.
• Learn the ECG wave names and what each shows, since ECG questions are a standard type. Add the disorders as one-line facts.

Two readings and one drawing of the heart are enough for the main content. The NEET Biology preparation guide shows how this fits with the other Human Physiology chapters, and the NEET syllabus lists the units.

Take a full Body Fluids and Circulation test on PrepMatic

After you have drawn the heart and the cardiac cycle, take a topic test on PrepMatic (about 15 questions in 30 minutes). The result uses NEET's negative marking, and the free Basic plan includes topic tests. The practice hub has other Human Physiology chapters.

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