Body Fluids and Circulation – Daily Practice Problem (DPP)

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🎯 NEET 2026 Daily Practice Problem (DPP)

Topic: Body Fluids and Circulation | 20 High-Yield MCQs

Q1. Which of the following plasma proteins is primarily involved in the coagulation of blood?

  1. Globulins
  2. Albumins
  3. Fibrinogen
  4. Serum amylase
✅ View Answer & Explanation

Correct Answer: (3) Fibrinogen
Explanation: Fibrinogens are needed for clotting or coagulation of blood. Globulins are involved in defense mechanisms, and albumins help in osmotic balance.

Q2. Erythroblastosis foetalis can occur when:

  1. Mother is Rh+ and Foetus is Rh-
  2. Mother is Rh- and Foetus is Rh+
  3. Both are Rh-
  4. Both are Rh+
✅ View Answer & Explanation

Correct Answer: (2) Mother is Rh- and Foetus is Rh+
Explanation: This Rh incompatibility leads to the mother developing antibodies against the Rh antigen of the foetus during the first delivery, which may attack the RBCs of the Rh+ foetus in subsequent pregnancies.

Q3. A person with blood group ‘O’ is called a universal donor because:

  1. They lack antigens A and B on RBCs
  2. They lack antibodies in plasma
  3. They have both antigens A and B
  4. They have Rh antigen
✅ View Answer & Explanation

Correct Answer: (1) They lack antigens A and B on RBCs
Explanation: Group O RBCs lack A and B antigens, so they don’t trigger an immune response in recipients of other groups. Group AB is the universal recipient as it lacks antibodies.

Q4. The enzyme responsible for the conversion of inactive Fibrinogen to Fibrin is:

  1. Thrombokinase
  2. Thrombin
  3. Renin
  4. Epinephrine
✅ View Answer & Explanation

Correct Answer: (2) Thrombin
Explanation: Prothrombin is converted to Thrombin by Thrombokinase. Thrombin then converts Fibrinogen to Fibrin threads which trap dead blood cells.

Q5. Which of the following is considered the ‘Pace-maker’ of the heart?

  1. AVN (Atrio-ventricular Node)
  2. Purkinje fibres
  3. SAN (Sino-atrial Node)
  4. Bundle of His
✅ View Answer & Explanation

Correct Answer: (3) SAN (Sino-atrial Node)
Explanation: SAN can generate the maximum number of action potentials (70-75/min) and is responsible for initiating and maintaining the rhythmic contractile activity of the heart.

Q6. During a joint diastole, which valves are open?

  1. Semilunar valves
  2. Tricuspid and Bicuspid valves
  3. Only Tricuspid valve
  4. Only Bicuspid valve
✅ View Answer & Explanation

Correct Answer: (2) Tricuspid and Bicuspid valves
Explanation: In joint diastole, all four chambers are relaxed. Tricuspid and bicuspid valves are open to allow blood from pulmonary veins/vena cava to flow into ventricles. Semilunar valves are closed.

Q7. The second heart sound (Dub) is associated with:

  1. Closure of AV valves
  2. Closure of Semilunar valves
  3. Opening of AV valves
  4. Opening of Semilunar valves
✅ View Answer & Explanation

Correct Answer: (2) Closure of Semilunar valves
Explanation: The first sound (Lubb) is the closure of tricuspid/bicuspid valves. The second sound (Dub) is the closure of semilunar valves at the start of ventricular diastole.

Q8. In a standard ECG, the T-wave represents:

  1. Depolarisation of atria
  2. Depolarisation of ventricles
  3. Repolarisation of ventricles
  4. Repolarisation of atria
✅ View Answer & Explanation

Correct Answer: (3) Repolarisation of ventricles
Explanation: P-wave: Atrial depolarisation; QRS complex: Ventricular depolarisation; T-wave: Ventricular repolarisation (return to normal state).

Q9. Cardiac output is defined as:

  1. Stroke Volume + Heart Rate
  2. Stroke Volume × Heart Rate
  3. Blood pressure × Heart Rate
  4. Stroke Volume / Heart Rate
✅ View Answer & Explanation

Correct Answer: (2) Stroke Volume × Heart Rate
Explanation: Cardiac output = 70 mL × 72 beats/min ≈ 5000 mL or 5 Litres per minute in a healthy adult.

Q10. The hepatic portal system carries blood from:

  1. Liver to Kidney
  2. Intestine to Liver
  3. Heart to Liver
  4. Liver to Heart
✅ View Answer & Explanation

Correct Answer: (2) Intestine to Liver
Explanation: The hepatic portal vein drains blood from the digestive tract to the liver before it is delivered to the systemic circulation.

Q20. Which of the following leucocytes are phagocytic cells?

  1. Basophils and Eosinophils
  2. Neutrophils and Monocytes
  3. Lymphocytes and Basophils
  4. Eosinophils and Lymphocytes
✅ View Answer & Explanation

Correct Answer: (2) Neutrophils and Monocytes
Explanation: Neutrophils (most abundant) and monocytes (6-8%) are phagocytic cells which destroy foreign organisms entering the body.

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