Grade 11 : Biology - Circulation System (Set 4)

Question 1

Cell Type	Average Count (per mm³ of blood)	Primary Function
RBCs (Erythrocytes)	5 - 5.5 Million	Transport of respiratory gases
WBCs (Leukocytes)	6,000 - 8,000	Immune defense mechanism
Platelets (Thrombocytes)	150,000 - 350,000	Clotting of blood

Based on the table above, which cellular component is present in the highest numerical density in healthy human blood?

Accepted Answer

B) Erythrocytes

Answer

A) Leukocytes

Answer

C) Thrombocytes

Answer

D) Monocytes

Question 2

A patient's cardiac parameters are recorded as follows: Stroke Volume (SV) = 70 mL per beat, Heart Rate (HR) = 75 beats per minute.

Calculate the Cardiac Output (CO) for this patient using the formula $ ext{Cardiac Output} = ext{Stroke Volume} imes ext{Heart Rate}$.

Accepted Answer

C) 5.25 L/min

Answer

A) 4.50 L/min

Answer

B) 5.00 L/min

Answer

D) 5.50 L/min

Question 3

Sino-atrial Node (SAN) ---> Atrioventricular Node (AVN) ---> Bundle of His ---> Purkinje Fibres

Which structure in the cardiac conduction sequence acts as the primary pacemaker generating spontaneous action potentials?

Accepted Answer

A) Sino-atrial Node (SAN)

Answer

B) Atrioventricular Node (AVN)

Answer

C) Bundle of His

Answer

D) Purkinje Fibres

Question 4

Cell Type	Average Count (per mm³ of blood)	Primary Function
RBCs (Erythrocytes)	5 - 5.5 Million	Transport of respiratory gases
WBCs (Leukocytes)	6,000 - 8,000	Immune defense mechanism
Platelets (Thrombocytes)	150,000 - 350,000	Clotting of blood

Identify Vessel X, Vessel Y, and Vessel Z respectively based on structural characteristics.

Accepted Answer

C) Artery, Vein, Capillary

Answer

A) Vein, Artery, Capillary

Answer

B) Capillary, Vein, Artery

Answer

D) Artery, Capillary, Vein

Question 5

Cell Type	Average Count (per mm³ of blood)	Primary Function
RBCs (Erythrocytes)	5 - 5.5 Million	Transport of respiratory gases
WBCs (Leukocytes)	6,000 - 8,000	Immune defense mechanism
Platelets (Thrombocytes)	150,000 - 350,000	Clotting of blood

Why is an individual with blood group AB considered a universal recipient?

Accepted Answer

B) They lack anti-A and anti-B antibodies in their plasma.

Answer

A) They lack antigens on their RBC membrane.

Answer

C) They produce both Anti-A and Anti-B antibodies.

Answer

D) Their RBCs contain no surface proteins.

Question 6

In a standard ECG tracing, electrical cardiac events are represented by specific waves: P-wave, QRS complex, and T-wave.

What physiological event is specifically represented by the QRS complex?

Accepted Answer

D) Depolarisation of the ventricles

Answer

A) Depolarisation of the atria

Answer

B) Repolarisation of the ventricles

Answer

C) Repolarisation of the atria

Question 7

Prothrombin --(Enzyme X)--> Thrombin; Fibrinogen --(Thrombin)--> Fibrin Clot

Identify Enzyme X responsible for converting inactive prothrombin into active thrombin during blood coagulation.

Accepted Answer

A) Thrombokinase (Prothrombinase)

Answer

B) Pepsin

Answer

C) Enterokinase

Answer

D) Fibrinolysin

Question 8

An Rh-negative mother carries an Rh-positive fetus during her second pregnancy. Without medical intervention, maternal anti-Rh antibodies cross the placenta.

What clinical condition can develop in the fetus/newborn as a result of Rh incompatibility?

Accepted Answer

C) Erythroblastosis Fetalis

Answer

A) Atherosclerosis

Answer

B) Hypertension

Answer

D) Angina Pectoris

Question 9

Right Ventricle ---> Pulmonary Artery ---> Lungs ---> Pulmonary Vein ---> Left Atrium

Which circulatory circuit is defined by the pathway shown above?

Accepted Answer

B) Pulmonary Circulation

Answer

A) Systemic Circulation

Answer

C) Hepatic Portal Circulation

Answer

D) Coronary Circulation

Question 10

The standard cardiac cycle duration in a human heart beating at 75 beats per minute is 0.8 seconds.

What is the duration of joint diastole during a single cardiac cycle?

Accepted Answer

C) 0.4 seconds

Answer

A) 0.1 seconds

Answer

B) 0.3 seconds

Answer

D) 0.7 seconds

Question 11

Lymph (tissue fluid) is collected by the lymphatic system and eventually drained back into major veins.

Compared to blood plasma, lymph lacks significant amounts of which component?

Accepted Answer

A) Larger plasma proteins and red blood cells

Answer

B) White blood cells

Answer

C) Water and soluble mineral salts

Answer

D) Glucose and amino acids

Question 12

Cell Type	Average Count (per mm³ of blood)	Primary Function
RBCs (Erythrocytes)	5 - 5.5 Million	Transport of respiratory gases
WBCs (Leukocytes)	6,000 - 8,000	Immune defense mechanism
Platelets (Thrombocytes)	150,000 - 350,000	Clotting of blood

Which of the following blood cells is classified as an agranulocyte?

Accepted Answer

D) Monocyte

Answer

A) Eosinophil

Answer

B) Basophil

Answer

C) Neutrophil

Question 13

Heart Valves: Tricuspid valve (between Right Atrium & Right Ventricle); Bicuspid/Mitral valve (between Left Atrium & Left Ventricle).

What is the primary function of these AV valves during ventricular contraction (systole)?

Accepted Answer

B) To prevent the backflow of blood into the atria

Answer

A) To allow blood to flow back from ventricles into atria

Answer

C) To pump blood into the aorta

Answer

D) To slow down cardiac electrical impulses

Question 14

A standard blood pressure reading of a healthy adult is written as 120/80 mm Hg.

What does the higher value (120 mm Hg) indicate?

Accepted Answer

C) Systolic pressure (pumping contraction pressure)

Answer

A) Diastolic pressure (resting pressure)

Answer

B) Atrial pressure during joint diastole

Answer

D) Capillary hydrostatic pressure

Question 15

During emergency physical exertion, the sympathetic nervous system triggers physiological changes in the heart.

How does sympathetic neural signaling affect cardiac function?

Accepted Answer

A) Increases heart rate and strength of ventricular contraction

Answer

B) Decreases heart rate and cardiac output

Answer

C) Inhibits SA node action potential generation

Answer

D) Reduces speed of conduction down the AV node

Question 16

Plasma accounts for ~55% of blood volume. Water forms 90-92% of plasma, while proteins form 6-8%.

Which major plasma protein is primarily responsible for maintaining blood colloidal osmotic balance?

Accepted Answer

D) Albumin

Answer

A) Fibrinogen

Answer

B) Globulin

Answer

C) Prothrombin

Question 17

Digestive Tract Capillaries ---> Hepatic Portal Vein ---> Liver Capillaries ---> Hepatic Vein ---> Inferior Vena Cava

Which specialized vascular connection routes nutrient-rich venous blood from the intestine to the liver before entering systemic circulation?

Accepted Answer

B) Hepatic Portal System

Answer

A) Renal Portal System

Answer

C) Hypophyseal Portal System

Answer

D) Coronary Circulation System

Question 18

Deposition of calcium, fat, cholesterol, and fibrous tissue reduces the arterial lumen diameter supplying heart musculature.

Which cardiovascular condition describes this arterial lumen narrowing?

Accepted Answer

A) Atherosclerosis (Coronary Artery Disease)

Answer

B) Heart Failure

Answer

C) Rheumatic Fever

Answer

D) Cardiac Arrest

Question 19

During a cardiac cycle, two prominent heart sounds ('lub' and 'dub') are produced and easily heard via a stethoscope.

The first heart sound ('lub') is associated with which event?

Accepted Answer

C) Closure of tricuspid and bicuspid valves

Answer

A) Opening of semilunar valves

Answer

B) Closure of semilunar valves

Answer

D) Opening of AV valves

Question 20

Cell Type	Average Count (per mm³ of blood)	Primary Function
RBCs (Erythrocytes)	5 - 5.5 Million	Transport of respiratory gases
WBCs (Leukocytes)	6,000 - 8,000	Immune defense mechanism
Platelets (Thrombocytes)	150,000 - 350,000	Clotting of blood

Which animal group exhibits incomplete double circulation due to a single unseparated ventricle?

Accepted Answer

B) Amphibians

Answer

A) Mammals

Answer

C) Fishes

Answer

D) Birds

Grade 11 : Biology - Circulation System (Set 4)