Answer:
E. Variations in Earth's orbit occur gradually over 100,000 years.
A volcanic winter is a reduction in global temperatures caused by volcanic ash and droplets of sulfuric acid and water obscuring the Sun and raising Earth's albedo (increasing the reflection of solar radiation) after a large, particularly explosive volcanic eruption.
Answer:
Organisms depends on physical and biological factors of an ecosystem.
Explanation:
Biological and physical changes cause shift in an ecosystem's populations because the population of organisms depends and greatly affected from the environmental factors such as temperature, moisture etc. These environmental factors causes change in the physical features of an ecosystem so when these changes occur in physical factors, it greatly affected the population of organisms.
I believe that it's called an adaptation.
Hope I helped you
Can you add the picture or describe it to me? Right now I'd guess that it's probably bacteria because bacteria breaks it down into ammonium and nitrate, which is taken up by the plants by a process of nitrogen fixation. So, D.