BrainIt

Biology · chapter PYQs

Body Fluids and Circulation, on the exam screen.

7 questions from NEET 2026, Re-NEET 2026, NEET 2020, 7 minutes, marked +4 / −1. See them with solutions.

Body Fluids and Circulation · PYQs

Candidate: You

Time Left

Q1/7

  1. Question 1 · NEET 2026 · Q150 · +4 / −1

    The WBC count of a person's blood sample is 8000/cu mm. How many eosinophils and lymphocytes would be in the same blood sample approximately?

    Answer and explanation

    Answer: (2)

    Eosinophils make up roughly 2-3% of total white blood cells (WBCs), so in 8000/cu mm that is about 160-240/cu mm. Lymphocytes make up about 20-25%, giving about 1600-2000/cu mm. Only option (2) provides both correct ranges.

  2. Question 2 · NEET 2026 · Q157 · +4 / −1

    Select the incorrect statement with reference to Rh grouping :

    Statement I: Erythroblastosis foetalis is a condition observed having foetus with Rh-ve blood and mother with Rh+ve blood.
    Statement II: Rh antigen is observed on RBCs in the majority of human beings.
    Statement III: Before blood transfusion, Rh group should also be matched.
    Statement IV: Rh incompatibility is observed when a pregnant mother is Rh-ve and the foetus is Rh+ve.
    Statement V: Erythroblastosis foetalis can be avoided by administering anti-Rh antibodies to the mother immediately after the delivery of the second child.

    Choose the answer from the options given below:

    Answer and explanation

    Answer: (3)

    Erythroblastosis foetalis can develop when an Rh-negative mother carries an Rh-positive foetus and becomes sensitised to the Rh antigen. In the NCERT account, anti-Rh antibodies are given immediately after delivery of the first child to prevent the disease in later pregnancies. Statement I reverses the mother–foetus Rh types, and Statement V gives the wrong timing; these are the two incorrect statements.

  3. Question 3 · Re-NEET 2026 · Q115 · +4 / −1

    The number of action potentials generated by sino-atrial node (SAN) in a healthy human is _______ per minute.

    Answer and explanation

    Answer: (2)

    The sino-atrial node is the pacemaker of the heart because it generates action potentials faster than any other part of the conducting system - about 70 to 75 per minute, which sets the normal resting heart rate. The atrio-ventricular node and Purkinje fibres can also fire spontaneously but at slower rates, so they only take over if the SAN fails. NCERT Class 11, Body Fluids and Circulation.

  4. Question 4 · Re-NEET 2026 · Q117 · +4 / −1

    Which of the following statements is incorrect?

    Answer and explanation

    Answer: (4)

    During blood coagulation, thrombin converts soluble plasma fibrinogen into insoluble fibrin threads. Those threads form a mesh that traps blood cells to make the clot. Reversing fibrin and fibrinogen gives the wrong direction for this step.

  5. Question 5 · Re-NEET 2026 · Q149 · +4 / −1

    The opening between the right atrium and the right ventricle is guarded by _________.

    Answer and explanation

    Answer: (2)

    The right atrioventricular opening is guarded by a valve of three muscular flaps or cusps, hence the tricuspid valve. The left side carries the bicuspid or mitral valve with two cusps. An easy mnemonic is that 'tri' goes with 'right'. NCERT Class 11, Body Fluids and Circulation.

  6. Question 6 · NEET 2020 · Q5 · +4 / −1

    The QRS complex in a standard ECG represents

    Answer and explanation

    Answer: (2)

    The QRS complex in a standard electrocardiogram (ECG) represents the depolarisation of the ventricles, which initiates ventricular contraction. Chapter: Body Fluids and Circulation.

  7. Question 7 · NEET 2020 · Q73 · +4 / −1

    Match the following columns and select the correct option.

    List I

    List II

    P) Eosinophils

    I) Immune response

    Q) Basophils

    II) Phagocytosis

    R) Neutrophils

    III) Release histaminase and destructive enzymes

    S) Lymphocytes

    IV) Release granules containing histamine

    Answer and explanation

    Answer: (4)

    Eosinophils release histaminase and destructive enzymes; basophils release histamine-containing granules; neutrophils are phagocytic; and lymphocytes mediate immune responses. Thus P-III, Q-IV, R-II, S-I. Chapter: Body Fluids and Circulation.