Question

Algae float on water during day time and sink during night time because

• A. they become light due to consumption of food material in respiration.
• B. they become buoyant in light due to the accumulation of oxygen bubbles released in photosynthesis.
• C. of accumulation of organic acids at night.
• D. of change in temperature.

Answer 1

Answer: (B)

Algae float in water during day time due to accumulation of oxygen bubbles form during photosynthesis. This oxygen is utilized during the life processes and respiration and hence they sink during night.