What percentage of the total global carbon is contained in the atmosphere (in $\%$)?

What is the percentage of $\text{PAR}$ in the incident solar radiations?

Consider the following statements about the carbon cycle and choose how many statements are correct?
$(a)$ The atmosphere contains $71\;\%$ of the total global carbon.
$(b)$ Decomposers contribute substantially to the $CO_2$ pool by processing waste materials and dead organic matter from land or oceans.
$(c)$ $4 \times 10^{13}\; kg$ of carbon is fixed through photosynthesis annually.
$(d)$ There is no respiratory input into the atmosphere.
$(e)$ Carbon constitutes $49\;\%$ of the dry weight of organisms.

The amount of nutrients, such as carbon, nitrogen, phosphorus, and calcium, present in the soil at any given time is referred to as:

Where does the bulk of $CO_2$ fixation occur?

Describe the components of an ecosystem.