Default Title

Question (31)

QN0036052

Which feature of alveoli most directly increases the efficiency of gas exchange?

(A) Thick muscular walls
(B) Large surface area and extensive blood-vessel network
(C) Absence of blood supply
(D) Small number of alveoli

Correct Answer: B

Explanation:

Alveoli provide a large exchange surface and have extensive blood vessels close to their thin walls.

Link:

Report Error

Question (32)

QN0036053

If the diaphragm flattens and the chest cavity becomes larger, what happens?

(A) Air is forced out of the lungs
(B) Air is drawn into the lungs
(C) Blood stops flowing
(D) Alveoli collapse immediately

Correct Answer: B

Explanation:

Expansion of the chest cavity creates conditions that suck air into the lungs.

Link:

Report Error

Question (33)

QN0036054

Why is haemoglobin important in human respiration?

(A) It carries oxygen to tissues
(B) It digests proteins
(C) It produces bile
(D) It filters urine

Correct Answer: A

Explanation:

Haemoglobin in red blood corpuscles has a high affinity for oxygen and transports it to tissues.

Link:

Report Error

Question (34)

QN0036055

The alveolar surface in a human lung would cover about 80 m² if spread out. What is the main advantage of such a large surface?

(A) Greater area for exchange of gases
(B) Greater storage of food
(C) Greater production of urine
(D) Greater pumping of blood

Correct Answer: A

Explanation:

A large surface area increases the efficiency of oxygen and carbon dioxide exchange.

Link:

Report Error

Question (35)

QN0036056

A person's blood contains insufficient haemoglobin. Which transport function would be directly affected?

(A) Transport of oxygen
(B) Transport of digested fats only
(C) Transport of urine
(D) Transport of bile

Correct Answer: A

Explanation:

Haemoglobin is the respiratory pigment responsible for carrying oxygen in red blood corpuscles.

Link:

Report Error

Question (36)

QN0036057

Which combination correctly represents the major components of the human circulatory system?

(A) Heart, blood and blood vessels
(B) Lungs, kidneys and ureters
(C) Stomach, intestine and liver
(D) Xylem, phloem and roots

Correct Answer: A

Explanation:

The circulatory system consists of the heart, blood and blood vessels.

Link:

Report Error

Question (37)

QN0036058

Why does the human heart have separate chambers for oxygenated and deoxygenated blood?

(A) To prevent their mixing and allow efficient oxygen supply
(B) To prevent digestion
(C) To produce urine
(D) To transport food only

Correct Answer: A

Explanation:

Separation allows efficient oxygen supply, especially important for organisms with high energy needs.

Link:

Report Error

Question (38)

QN0036059

Which chamber pumps oxygenated blood from the heart to the rest of the body?

(A) Right atrium
(B) Right ventricle
(C) Left atrium
(D) Left ventricle

Correct Answer: D

Explanation:

The left ventricle pumps oxygen-rich blood to the rest of the body.

Link:

Report Error

Question (39)

QN0036060

Why are the walls of ventricles thicker than those of atria?

(A) Ventricles pump blood out to major destinations
(B) Atria contain no blood
(C) Ventricles produce oxygen
(D) Atria perform digestion

Correct Answer: A

Explanation:

Ventricles must pump blood into the lungs or the rest of the body, requiring stronger muscular walls.

Link:

Report Error

Question (40)

QN0036061

A valve in the heart becomes unable to function properly. Which process would be directly affected?

(A) Preventing backward flow of blood
(B) Digestion of fats
(C) Formation of urine
(D) Absorption of water by roots

Correct Answer: A

Explanation:

Heart valves ensure that blood does not flow backwards when chambers contract.

Link:

Report Error

Question (31)

Which feature of alveoli most directly increases the efficiency of gas exchange?

Explanation:

Link:

Question (32)

If the diaphragm flattens and the chest cavity becomes larger, what happens?

Explanation:

Link:

Question (33)

Why is haemoglobin important in human respiration?

Explanation:

Link:

Question (34)

The alveolar surface in a human lung would cover about 80 m² if spread out. What is the main advantage of such a large surface?

Explanation:

Link:

Question (35)

A person's blood contains insufficient haemoglobin. Which transport function would be directly affected?

Explanation:

Link:

Question (36)

Which combination correctly represents the major components of the human circulatory system?

Explanation:

Link:

Question (37)

Why does the human heart have separate chambers for oxygenated and deoxygenated blood?

Explanation:

Link:

Question (38)

Which chamber pumps oxygenated blood from the heart to the rest of the body?

Explanation:

Link:

Question (39)

Why are the walls of ventricles thicker than those of atria?

Explanation:

Link:

Question (40)

A valve in the heart becomes unable to function properly. Which process would be directly affected?

Explanation:

Link:

Excel With Tutors

ExcelWithTutors

For Student

For Tutors

Learn

OUR POLICY