Body fluids and circulation practice · Mixed difficulty

Option C (190/110 mmHg may harm vital organs like brain and kidney) is correct because this blood pressure reading is severely hypertensive and poses a significant risk to organ function.

Option A (Level of HDL is high due to oestrogen production) is correct because estrogen increases HDL levels, which helps protect against heart attacks.

Option B (Adrenaline) is correct because adrenaline is released during stressful situations, increasing heart rate.

Option D (A only) is correct because the genotypes $I^B i$, $I^A i$, and $ii$ are the only possible combination that results in the given blood groups for father, mother, and child respectively.

Option A (Sympathetic nerve input to skeletal muscle causes the blood vessels in the muscle to dilate) is correct because while sympathetic stimulation can cause vasodilation, it is primarily due to local metabolic factors, not direct sympathetic input.

Option C (Depolarisation of ventricles) is correct because the QRS complex represents the electrical activity associated with ventricular depolarization, leading to ventricular contraction.

Option A (Medulla oblongata) is correct because cardiovascular reflexes, which regulate blood pressure and heart rate, are primarily controlled by the medulla oblongata.

Option D (SA node $\to$ AV node $\to$ Bundle of his $\to$ Purkinje fibres $\to$ Heart muscle) is correct because it represents the correct sequence of impulse conduction in the heart.

Option B (Rh positive (Rh + ve)) is correct because individuals with the Rh antigen on their red blood cells are classified as Rh positive.

Option D (Both (a) and (b)) is correct because lymph transports both nutrients and hormones, facilitating their distribution throughout the body.

Option B (Bone marrow) is correct because bone marrow is the primary site of hematopoiesis, where blood cells, including primary blood cells, are formed.

Option C (More WBCs and no RBCs) is correct because lymph is a fluid derived from tissue fluid and contains white blood cells but lacks red blood cells.

Option A (atherosclerosis) is correct because coronary artery disease is often caused by atherosclerosis, the build-up of plaque in the arteries.

Option D (14th June) is correct because World Blood Donation Day is observed annually on June 14th to raise awareness about the need for safe blood and blood products.

Option B (Neutrophil, monocyte and macrophage) is correct because these cells are all capable of phagocytosis, engulfing and digesting pathogens and cellular debris.

Option A (Seal up wounds and prevent blood loss) is correct because the primary function of blood clotting is to stop bleeding by forming a clot at the site of injury.

Option A (Adrenal) is correct because the adrenal glands secrete hormones like adrenaline that affect blood pressure.

Option B (Coronary artery) is correct because the coronary arteries supply blood to the heart muscle (myocardium) and the pericardium.

Option B (Thoracic duct) is correct because the thoracic duct is the largest lymphatic vessel in the human body.

Option C (Due to the absence of Rh antibodies in mother’s blood) is correct because the mother's immune system has not yet been exposed to the Rh antigen and therefore has not produced Rh antibodies.

Option D (The return of the ventricles from excited to normal state) is correct because the T-wave in an ECG represents ventricular repolarization.

Option A (I and II) is correct because reptiles and amphibians have incomplete double circulation due to the mixing of oxygenated and deoxygenated blood in their single ventricle.

Option $\mathrm{I^BI^B}$ is correct because if the mother is $\mathrm{I_BI_B}$, she can only contribute $\mathrm{I_B}$ allele, and for the child to be $\mathrm{I_AI_B}$, the father must contribute $\mathrm{I_A}$, which is not possible if the father is $\mathrm{I_BI_B}$.

Option C (Acidophils – Secrete heparin) is the unmatched one because acidophils (eosinophils) are involved in allergic reactions and parasitic infections, and they do NOT secrete heparin. Heparin is secreted by basophils.

Option C (Fibrinogen) is correct because Fibrinogen is a plasma protein directly involved in the blood coagulation process, converting into fibrin to form the clot.

Option B (Heart) is correct because atrial natriuretic hormone (ANH) is produced by the atria of the heart.

Option B (B and AB) is correct because a person with blood group B can donate blood to individuals with blood group B and AB due to the presence of B antigens on their red blood cells.

Option C (Factor X) is correct because both the intrinsic and extrinsic pathways converge at the activation of Factor X, leading to the common pathway of blood coagulation.

Option C (If Assertion is true but Reason is false) is correct because while the assertion about slow blood velocity in prawn lacunae and sinuses is true, the reason incorrectly states that prawns lack a heart.

Option A (ANS (Autonomic Nervous System)) is correct because the medulla oblongata uses the autonomic nervous system to regulate cardiac function.