Which of the following is(are) TRUE of photoautotrophs?
A)They are responsible for the first concentration of free oxygen in the atmosphere.
B)They are responsible for an early extinction of most anaerobic organisms.
C)They are carbon-rich food baskets for heterotrophs.
D)They are responsible for the presence of the ozone layer of the atmosphere
E)All of these are true.

Question

Quizplus · Accepted Answer

Photoautotrophs, such as cyanobacteria and plants, contributed to the oxygenation of the atmosphere, leading to the formation of the ozone layer and the extinction of many anaerobic organisms. They also serve as a primary food source for heterotrophs.

Which of the Following Is(are) TRUE of Photoautotrophs