Biology - Circulatory System Questions for SSC CGL (with Answers)

Answer: C. Sphygmomanometer

A sphygmomanometer measures blood pressure using an inflatable cuff and a pressure gauge.

Answer: B. Haemoglobin

Haemoglobin, an iron-containing protein in RBCs, binds oxygen and transports it.

Answer: C. Platelets

Platelets (thrombocytes) help form clots and stop bleeding at wounds.

Answer: A. Four

The human heart has four chambers: two atria and two ventricles.

Answer: D. Aorta

The aorta is the largest artery; it carries oxygenated blood from the left ventricle to the body.

Answer: C. Pulmonary artery

The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs.

Answer: D. Left ventricle

The left ventricle pumps oxygenated blood into the aorta for supply to the whole body.

Answer: B. Vitamin K

Vitamin K is needed to make clotting factors such as prothrombin in the liver.

Answer: B. Nucleus

Mature mammalian RBCs lose their nucleus, allowing more room for haemoglobin.

Answer: C. Red bone marrow

In adults, RBCs are formed in the red bone marrow of bones.

Answer: B. Pulmonary vein

Pulmonary veins carry oxygenated blood from the lungs to the left atrium.

Answer: A. Heparin

Heparin is an anticoagulant that prevents clotting inside blood vessels; the others help clotting.

Answer: A. Bicuspid (mitral) valve

The bicuspid or mitral valve, with two cusps, guards the opening between the left atrium and left ventricle.

Answer: B. Sino-atrial (SA) node

The SA node in the right atrium generates the impulses that start each heartbeat.

Answer: A. About 120 days

Human RBCs survive for about 120 days before being removed from circulation.