Question

Identify the factors contributing to the high oxygen content in the surface layer of water.

1. High rates of respiration by aquatic organisms.
2. Maximum production of oxygen through photosynthesis.
3. Limited contact with the atmosphere, reducing oxygen diffusion.
4. Presence of decomposers actively consuming oxygen.

• A. 1 only
• B. 2 only
• C. 3, 4
• D. 3 only

Answer 1

Answer:

B. 2 only

OXYGEN STRATIFICATION

• The surface layer has the maximum oxygen content due to two main reasons.

• Being well lighted, maximum photosynthetic oxygen is produced here.

• Being in intimate contact with the atmosphere, it permits free diffusion of oxygen into it from the air.