Author Question: Earth's first atmosphere was rich in water vapor but poor in free oxygen. The atmosphere became more ... (Read 115 times)

Pineapplelove6

  • Hero Member
  • *****
  • Posts: 560
Earth's first atmosphere was rich in water vapor but poor in free oxygen. The atmosphere became more oxygenated with the
 
  A) development of the ozone layer.
  B) emergence of stromatolites that developed a simple version of photosynthesis.
  C) emergence of gases from volcanic eruptions.
  D) both A and B.

Question 2

What was the one most important event in the Precambrian?
 
  What will be an ideal response?



flexer1n1

  • Sr. Member
  • ****
  • Posts: 373
Answer to Question 1

Answer: B

Answer to Question 2

Answer: The accumulation of free oxygen in the atmosphere. This allowed the ozone layer to form and allowed life to emerge.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

The most dangerous mercury compound, dimethyl mercury, is so toxic that even a few microliters spilled on the skin can cause death. Mercury has been shown to accumulate in higher amounts in the following types of fish than other types: swordfish, shark, mackerel, tilefish, crab, and tuna.

Did you know?

A seasonal flu vaccine is the best way to reduce the chances you will get seasonal influenza and spread it to others.

Did you know?

Stroke kills people from all ethnic backgrounds, but the people at highest risk for fatal strokes are: black men, black women, Asian men, white men, and white women.

Did you know?

Adolescents often feel clumsy during puberty because during this time of development, their hands and feet grow faster than their arms and legs do. The body is therefore out of proportion. One out of five adolescents actually experiences growing pains during this period.

Did you know?

Your skin wrinkles if you stay in the bathtub a long time because the outermost layer of skin (which consists of dead keratin) swells when it absorbs water. It is tightly attached to the skin below it, so it compensates for the increased area by wrinkling. This happens to the hands and feet because they have the thickest layer of dead keratin cells.

For a complete list of videos, visit our video library