During photosynthesis,what percentage of incident solar radiation is utilized by higher plants?

When the intake of $CO_2$ and the release of $O_2$ are equal during photosynthesis and respiration,the condition is known as:

Intensity of light can be measured by

Which of the following is an effect of herbicides?

Maximum solar energy may be trapped by

Photosynthetic organisms occur at different depths in the ocean. Do they receive qualitatively and quantitatively the same light? How do they adapt to carry out photosynthesis under these conditions?