The answer is population density
I believe you would first check the river to make sure it's polluted then you would have to check how/if the chemical plant is involved. Also see if other factors other than the chemical plant is contaminating the river.
I hope this helps!
Answer:
I think A. gaseous cycles involve elements that are abundantly found in the gaseous state
Explanation:
This photo shows the differences between phloem and xylem/functions of stems
description of root: is the organ of a plant that typically lies below the surface of the soil.
function of roots: absorption of water
storage of food and nutrients
description of leaves: organ of a vascular plant
function of leaves: gas exchange occurs here!!!
1) leaves have large SA for fast diffusion
2) contain many stomata to allow movement of gases into and out of the leaf.