Class 11 Biology (NCERT / JAC Board)

1. What percentage of human blood is constituted by plasma?

• A. 55%
• B. 45%
• C. 90%
• D. 60%

2. Which plasma protein is primarily responsible for osmotic balance in the blood?

• A. Albumins
• B. Globulins
• C. Fibrinogen
• D. Prothrombin

3. Which leukocyte is the most abundant type in human blood?

• A. Neutrophils
• B. Lymphocytes
• C. Monocytes
• D. Basophils

4. Which blood group is known as the universal donor?

• A. O negative (O-ve)
• B. AB positive (AB+ve)
• C. A positive (A+ve)
• D. B negative (B-ve)

5. Erythroblastosis fetalis can occur when the mother is Rh-negative and the fetus is:

• A. Rh-positive
• B. Rh-negative
• C. ABO incompatible
• D. O negative

6. The natural pacemaker of the human heart is the:

• A. Sino-atrial node (SAN)
• B. Atrio-ventricular node (AVN)
• C. Bundle of His
• D. Purkinje fibers

7. In a normal ECG, the P-wave represents:

• A. Depolarisation of the atria
• B. Depolarisation of the ventricles
• C. Repolarisation of the ventricles
• D. Repolarisation of the atria

8. The volume of blood pumped out by each ventricle during a single cardiac cycle is known as:

• A. Stroke volume (~70 mL)
• B. Cardiac output (~5000 mL)
• C. Tidal volume (~500 mL)
• D. End-diastolic volume (~120 mL)

9. The first heart sound ('Lub') is associated with the closure of:

• A. Tricuspid and bicuspid (mitral) valves
• B. Semilunar valves
• C. Aortic valve only
• D. Pulmonary valve only

10. Blood pressure higher than 140/90 mm Hg is clinically termed as:

• A. Hypertension
• B. Hypotension
• C. Atherosclerosis
• D. Angina pectoris

11. Which blood vessel carries oxygenated blood from the lungs to the left atrium?

• A. Pulmonary vein
• B. Pulmonary artery
• C. Superior vena cava
• D. Aorta

12. Which ion plays a critical role in the blood clotting cascade?

• A. Calcium ions (Ca2+)
• B. Sodium ions (Na+)
• C. Potassium ions (K+)
• D. Iron ions (Fe2+)

13. The middle muscular layer of the heart wall is called:

• A. Myocardium
• B. Epicardium
• C. Endocardium
• D. Pericardium

14. Formed elements produced from megakaryocytes in the bone marrow are:

• A. Blood platelets (Thrombocytes)
• B. Erythrocytes
• C. Monocytes
• D. Eosinophils

15. Open circulatory system is found in which of the following animal groups?

• A. Arthropods and Molluscs
• B. Annelids and Chordates
• C. Vertebrates and Cephalopods
• D. Birds and Mammals

16. The hepatic portal system connects the digestive tract directly to the:

• A. Liver
• B. Kidney
• C. Heart
• D. Spleen

17. Acute chest pain due to inadequate oxygen reaching the heart muscle is called:

• A. Angina pectoris
• B. Heart failure
• C. Heart attack
• D. Cardiac arrest

18. Bicuspid valve (mitral valve) guards the opening between:

• A. Left atrium and left ventricle
• B. Right atrium and right ventricle
• C. Right ventricle and pulmonary artery
• D. Left ventricle and aorta

19. Neural signals through sympathetic nerves can increase heart rate by:

• A. Increasing rate of heartbeat and strength of ventricular contraction
• B. Decreasing heart rate and cardiac output
• C. Blocking action potential generation at SAN
• D. Dilating blood vessels exclusively

20. Lymph differs from blood in that lymph lacks:

• A. RBCs and larger plasma proteins
• B. WBCs
• C. Water
• D. Glucose and nutrients

21. The average lifespan of human Red Blood Cells (RBCs) is:

• A. 120 days
• B. 30 days
• C. 7 days
• D. 365 days

22. Which organ is known as the graveyard of RBCs?

• A. Spleen
• B. Liver
• C. Bone marrow
• D. Kidney

23. Standard cardiac output of a resting adult human is approximately:

• A. 5 Litres/minute
• B. 2 Litres/minute
• C. 10 Litres/minute
• D. 1 Litre/minute

24. In an ECG graph, the QRS complex represents:

• A. Depolarisation of ventricles
• B. Depolarisation of atria
• C. Repolarisation of ventricles
• D. Repolarisation of atria

25. Granulocytes among white blood cells include:

• A. Neutrophils, Eosinophils, Basophils
• B. Lymphocytes and Monocytes
• C. Monocytes and Neutrophils
• D. Lymphocytes and Basophils

26. Which type of WBC secretes histamine, serotonin, and heparin involved in inflammatory reactions?

• A. Basophils
• B. Neutrophils
• C. Monocytes
• D. Lymphocytes

27. Human heart is described as myogenic because:

• A. Heartbeat originates in specialized nodal muscle tissue
• B. Heartbeat originates from external motor nerve impulses
• C. Heart consists solely of smooth muscle
• D. Heart rate is completely voluntary

28. The second heart sound ('Dub') is caused by the closure of:

• A. Semilunar valves
• B. Atrioventricular valves
• C. Tricuspid valve only
• D. Bicuspid valve only

29. Deposition of calcium, fat, cholesterol, and fibrous tissue in coronary arteries leads to:

• A. Atherosclerosis (Coronary Artery Disease)
• B. Heart failure
• C. Rheumatic fever
• D. Pulmonary hypertension

30. Parasympathetic neural signals affect heart action by:

• A. Decreasing rate of heartbeat and cardiac output
• B. Increasing rate of heartbeat and cardiac output
• C. Increasing ventricular contraction strength
• D. Elevating blood pressure rapidly