Examine these statements regarding Blood Plasma Proteins and their properties:
(i) Fibrinogens, globulins, and albumins are the major proteins present in the blood plasma. (ii) Proteins contribute nearly 90–92 per cent of the total plasma volume. (iii) Coagulation factors are present in the plasma in an active form at all times. (iv) Plasma without the clotting factors is referred to as serum.
Explanation: Statement (ii) is incorrect because water constitutes about 90–92% of plasma, whereas proteins contribute only 6–8%. Statement (iii) is incorrect because clotting factors remain in an inactive form in plasma and become activated only during blood coagulation. Statements (i) and (iv) are correct.
Question 22 of 100
📘 CLASS XI
Consider these statements about human platelets (thrombocytes):
(i) Platelets are nucleated cells formed in the spleen. (ii) They are cell fragments produced from special cells called megakaryocytes in the bone marrow. (iii) Normal blood contains 15,000 to 35,000 platelets mm-3. (iv) A reduction in platelet number can lead to severe clotting disorders and excessive blood loss.
Explanation: Statement (i) is incorrect because platelets are non-nucleated cell fragments formed from megakaryocytes in the bone marrow. Statement (iii) is incorrect because the normal platelet count is about 1,50,000 to 3,50,000 mm-3. Statements (ii) and (iv) are correct.
Question 23 of 100
📘 CLASS XI
Examine these statements about standard ECG connection leads:
(i) To obtain a standard ECG, a patient is connected with three electrical leads: one to each wrist and one to the left ankle. (ii) Multiple leads are attached to the chest region for a detailed evaluation of heart function. (iii) The heart rate of an individual can be determined simply by counting the number of P-waves in a given time period. (iv) Any deviation from the standard ECG wave shape indicates a possible abnormality or disease.
Explanation: Statement (iii) is incorrect because heart rate is determined by counting the number of QRS complexes in a given time period, not P-waves. Statements (i), (ii), and (iv) are correct.
Question 24 of 100
📘 CLASS XI
Read these statements regarding Hepatic Portal and Coronary Systems:
(i) A unique vascular connection exists between the digestive tract and liver, called the hepatic portal system. (ii) The hepatic portal vein carries blood from the liver directly to the intestine. (iii) A special coronary system of blood vessels is present exclusively for blood circulation to and from cardiac musculature. (iv) Deoxygenated blood from the hepatic portal system is emptied directly into the stomach for filtration.
Explanation: Statement (ii) is incorrect because the hepatic portal vein carries blood from the digestive tract to the liver. Statement (iv) is incorrect because portal blood enters the liver before joining the systemic circulation and never passes into the stomach for filtration. Statements (i) and (iii) are correct.
Question 25 of 100
📘 CLASS XI
Read these statements about blood circulation in open and closed systems:
(i) In an open circulatory system, blood pumped by the heart passes into body cavities called sinuses. (ii) Closed circulatory systems are present in arthropods and molluscs. (iii) Annelids and chordates have a closed circulatory system. (iv) A closed circulatory pattern is considered more advantageous as the flow of fluid can be more precisely regulated.
Explanation: Statement (ii) is incorrect because arthropods and most molluscs possess an open circulatory system. Annelids and chordates possess a closed circulatory system, which allows more efficient and regulated blood flow. Statements (i), (iii), and (iv) are correct.
Question 26 of 100
📘 CLASS XI
Analyze the following statements about the composition and abundance of formed elements in human blood:
(i) Erythrocytes (RBCs) are the most abundant of all the cells in the blood. (ii) Leucocytes (WBCs) are nucleated and are relatively lesser in number, averaging 6,000–8,000 per mm-3 of blood. (iii) Platelets are cell fragments produced from specialized cells called megakaryocytes in the spleen. (iv) Granulocytes include neutrophils, eosinophils, and monocytes.
Explanation: Statements (i) and (ii) are correct. Statement (iii) is incorrect because megakaryocytes are present in the bone marrow, not the spleen. Statement (iv) is incorrect because monocytes are agranulocytes, whereas granulocytes include neutrophils, eosinophils, and basophils.
Question 27 of 100
📘 CLASS XI
Consider these statements regarding hemoglobin and respiratory gas transport:
(i) A healthy individual has 12–16 g of hemoglobin in every 100 mL of blood. (ii) Hemoglobin is a red-colored, magnesium-containing complex protein. (iii) Mature mammalian RBCs are biconcave and lack a nucleus in most species. (iv) RBCs have an average life span of 120 days, after which they are destroyed in the thymus.
Explanation: Statements (i) and (iii) are correct. Statement (ii) is incorrect because hemoglobin is an iron-containing protein, not a magnesium-containing one. Statement (iv) is incorrect because aged RBCs are mainly destroyed in the spleen, the "graveyard of RBCs", not the thymus.
Question 28 of 100
📘 CLASS XI
Study the statements regarding types of leucocytes (WBCs) and their functional features:
(i) Neutrophils are the most abundant WBCs (60–65%), whereas basophils are the least abundant (0.5–1%). (ii) Lymphocytes comprise 20–25% of the total WBCs and are of B and T forms. (iii) Monocytes are granulocytes that make up 6–8% of WBCs. (iv) Basophils are highly phagocytic cells that secrete histamine and heparin.
Explanation: Statements (i) and (ii) are correct. Statement (iii) is incorrect because monocytes are agranulocytes. Statement (iv) is incorrect because basophils secrete histamine, serotonin, and heparin but are not phagocytic cells.
Question 29 of 100
📘 CLASS XI
Read the statements below regarding ABO blood grouping compatibility:
(i) Blood group 'O' has anti-A and anti-B antibodies in its plasma and no antigens on RBCs. (ii) Blood group 'AB' has both A and B antigens on RBCs and no antibodies in the plasma. (iii) A person with blood group 'A' can safely receive blood from donors of groups 'A' and 'AB'. (iv) Antigen A and B are glycoproteins present on the surface of WBCs.
Explanation: Statements (i) and (ii) are correct. Statement (iii) is incorrect because a person with blood group A cannot receive blood from group AB due to the presence of B antigen. Statement (iv) is incorrect because ABO antigens are present on RBCs, not WBCs.
Question 30 of 100
📘 CLASS XI
Examine the following statements regarding the Rh factor and maternal-foetal incompatibility:
(i) Nearly 80 percent of human individuals are Rh positive (+ve). (ii) Rh factor mismatch during the first pregnancy leads to immediate erythroblastosis fetalis in the foetus. (iii) In erythroblastosis fetalis, maternal Rh antibodies leak into the foetal blood and destroy foetal RBCs. (iv) This condition can be avoided by administering anti-Rh antibodies to the mother immediately after the first delivery.
Explanation: Statements (i), (iii), and (iv) are correct. Statement (ii) is incorrect because the first pregnancy is usually unaffected due to placental separation of maternal and foetal blood. Erythroblastosis fetalis mainly affects subsequent Rh-positive pregnancies.
