Select all that apply.

fossils

a. form whenever an organism dies
b. can show evolutionary relationships between organisms
c. suggest modern day organisms evolved over time
d. can be grouped together by age to form a fossil record

In other words, physical or chemical parts of the environment that affect the organisms that are in that environment.

Explanation:

For aquatic ecosystems, these factors include light levels, water flow rate, temperature, dissolved oxygen, acidity (pH), salinity and depth. Light level is an important factor in aquatic ecosystems. hope this helps you :) god loves you :)