Question

The blood leaving the tissues becomes richer in

• A. carbon dioxide
• B. water
• C. haemoglobin
• D. oxygen

Answer 1

The correct option is A

carbon dioxide

Option A is correct

• During the process of respiration, carbon dioxide is released by the cells which enters the venous blood and is transported back to the heart, where it again goes through the process of oxygenation.

Explanation for incorrect options:

Option B:

• Water is used during the process of photosynthesis where it combines with carbon-dioxide to form glucose and oxygen.

Option C:

• Haemoglobin carries oxygen from lungs to the tissues.

Option D:

• Oxygen is released during the process of photosynthesis and is used by animals for the process of respiration.

The process of respiration supplies oxygen to the tissues via arteries and takes carbon-dioxide back via veins.