Question

Engelmann (1882) observed that motile aerobic bacteria accumulated near areas of a filament of Spirogyra which were illuminated by red or blue light but they did not accumulate near a filament illuminated with green light. From this, he inferred that:

• A. Chlorophyll absorbs green light.
• B. $O_2$ is released from $C{O}_2$ in the light reaction.
• C. $O_2$ is released from $H_{2}O$ in the light reaction.
• D. Red and blue light are more effective in photosynthesis.

Answer 1

The correct option is D

Red and blue light are more effective in photosynthesis.

He inferred that red and blue lights are more effective in photosynthesis. Photosynthesis in spirogyra was most effective under red or blue lights which attracted the aerobic bacteria to move towards them for the oxygen released.