Question

According to scientific evidence, earth’s earliest atmosphere lacked oxygen. Over time, oxygen was added to the atmosphere.

Which statements explain how this change occurred and how it affected life on earth?

Choose all answers that are correct. MULTIPLE ANSWERS!!

A) Photosynthesis was carried out as cyanobacteria evolved. Oxygen is needed to carry out photosynthesis.

B) Oxygen is needed to carry out many life processes. The addition of oxygen to the earth's atmosphere assisted with the development of eukaryotic organisms.

C) Oxygen is needed to carry out many life processes. The addition of oxygen to the earth's atmosphere assisted with the development of the first prokaryotic organisms.

D) Photosynthesis was carried out as cyanobacteria evolved. Oxygen is a product of photosynthesis.

Answer 1

The correct answers are:
B) Oxygen is needed to carry out many life processes. The addition of oxygen to the earth's atmosphere assisted with the development of eukaryotic organisms.
D) Photosynthesis was carried out as cyanobacteria evolved. Oxygen is a product of photosynthesis.

Answer 2

The following statements explain how oxygen was introduced into the earliest atmosphere of the Earth and how the presence of oxygen affected life on Earth.

B) Oxygen is needed to carry out many life processes. The addition of oxygen to the earth's atmosphere assisted with the development of eukaryotic organisms.

D) Photosynthesis was carried out as cyanobacteria evolved. Oxygen is a product of photosynthesis.