Which of the following statements are correct?
A.Basophils are most aboundant cell of the total WBCs.
B.Basophils secrete histamine, serotonin and heparin.
C.Basophils are involved in inflammatory response.
D.Basophils have kidney shaped nucleus.
E.Basophil are agranulocyte.
Choose the correct answer from the options given below:
AI-generated explanation. Check against your textbook.
Explanation:
Basophils are granulocytes; they are not the most abundant WBCs (neutrophils are). They release histamine and heparin, and participate in inflammatory and allergic responses. Their nucleus is typically bilobed or irregular, not kidney-shaped. They are not agranulocytes (they have granules). Therefore, statements B and C are correct, while A, D, and E are incorrect. Hence the answer is option 4 (B and C only).
🧠 Did You Know?
Basophils play a role in inflammation and hypersensitivity by releasing histamine, which increases blood flow and permeability of blood vessels.
💡 NCERT Memory Line:
Neutrophils are the most abundant WBCs; basophils are granulocytes that release histamine and heparin and are involved in inflammatory responses; they are not agranulocytes.
Given below are two statements: Statement I: The coagulum is formed of network of threads called thrombins. Statement II: Spleen is the graveyard of erythrocytes.
In the light of the above statements, choose the
most appropriate answer from the options given
below:
AI-generated explanation. Check against your textbook.
Explanation:
Statement I is incorrect: the coagulum (blood clot) is formed by a network of fibrin threads; thrombin converts fibrinogen into fibrin. So the proper term is fibrin, not thrombin, forming the clot. Statement II is correct: the spleen acts as the graveyard/returning site for old erythrocytes.
🧠 Did You Know?
Old erythrocytes are filtered and broken down in the spleen, and their components are reused in the body.
Which enzyme is responsible for the conversion of
inactive fibrinogens to fibrins?
AI-generated explanation. Check against your textbook.
Explanation:
Thrombin is the enzyme that converts soluble fibrinogen into insoluble fibrin strands, forming a clot. In the coagulation cascade, prothrombin is activated to thrombin, which then acts on fibrinogen to produce fibrin. This process is described in NCERT under digestive–circulatory related chapters, explaining how clot formation involves thrombin as the key enzyme.
🧠 Did You Know?
Renin helps convert angiotensinogen to angiotensin, influencing blood pressure, not fibrin formation. Epinephrine can affect blood flow and clotting indirectly but does not convert fibrinogen to fibrin. Thrombokinase is an older term sometimes used for the prothrombin activator complex that leads to thrombin formation, not the direct conversion of fibrinogen to fibrin.
💡 NCERT Memory Line:
Thrombin converts fibrinogen into fibrin, forming the mesh of a blood clot as described in NCERT biology chapters on blood coagulation.
Persons with 'AB' blood group are called as
"Universal recipients". This is due to:
AI-generated explanation. Check against your textbook.
Explanation:
People with AB blood group have both A and B antigens on their RBCs and no antibodies against A or B in the plasma. Therefore, they can receive blood from any ABO type without agglutination, making them universal recipients. The correct reason is the absence of anti-A and anti-B antibodies in plasma.
🧠 Did You Know?
In contrast, individuals with type O blood have anti-A and anti-B antibodies in their plasma, so they can donate to anyone but can receive only from type O.
💡 NCERT Memory Line:
Universal recipient AB: has both A and B antigens on RBCs and no anti-A or anti-B antibodies in plasma.
Which would be the heart rate of a person if the
cardiac output is 5L, blood volume in the ventricles
at the end of diastole is 100 mL and at the end of
ventricular systole is 50 mL?
AI-generated explanation. Check against your textbook.
Explanation:
Cardiac output (CO) = heart rate (HR) × stroke volume (SV). SV = end diastolic volume − end systolic volume = 100 mL − 50 mL = 50 mL = 0.05 L. Given CO = 5 L/min, so HR = CO/SV = 5 L/min ÷ 0.05 L = 100 beats per minute. Therefore, option 2 is correct. The other options would require different SV values: 50 bpm would need SV = 0.1 L, 75 bpm would need SV ≈ 0.0667 L, 125 bpm would need SV ≈ 0.04 L. NCERT emphasizes CO = HR × SV in normal heart function.
🧠 Did You Know?
Stroke volume depends on preload (EDV), afterload, and contractility. EDV here is the amount of blood in the ventricle at the end of diastole.
💡 NCERT Memory Line:
CO = HR × SV, where SV = EDV − ESV; use given CO and EDV/ESV to find HR.