« previous next »

Author Question: Earth's first atmosphere was rich in water vapor but poor in free oxygen. The atmosphere became more ... (Read 113 times)

Pineapplelove6

  • Hero Member
  • *****
  • Posts: 560
on: Jul 29, 2018
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
Reply #1 on: Jul 29, 2018
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
« previous next »
 

Did you know?

Signs of depression include feeling sad most of the time for 2 weeks or longer; loss of interest in things normally enjoyed; lack of energy; sleep and appetite disturbances; weight changes; feelings of hopelessness, helplessness, or worthlessness; an inability to make decisions; and thoughts of death and suicide.

Did you know?

One way to reduce acid reflux is to lose two or three pounds. Most people lose weight in the belly area first when they increase exercise, meaning that heartburn can be reduced quickly by this method.

Did you know?

Chronic necrotizing aspergillosis has a slowly progressive process that, unlike invasive aspergillosis, does not spread to other organ systems or the blood vessels. It most often affects middle-aged and elderly individuals, spreading to surrounding tissue in the lungs. The disease often does not respond to conventionally successful treatments, and requires individualized therapies in order to keep it from becoming life-threatening.

Did you know?

According to the National Institute of Environmental Health Sciences, lung disease is the third leading killer in the United States, responsible for one in seven deaths. It is the leading cause of death among infants under the age of one year.

Did you know?

Stevens-Johnson syndrome and Toxic Epidermal Necrolysis syndrome are life-threatening reactions that can result in death. Complications include permanent blindness, dry-eye syndrome, lung damage, photophobia, asthma, chronic obstructive pulmonary disease, permanent loss of nail beds, scarring of mucous membranes, arthritis, and chronic fatigue syndrome. Many patients' pores scar shut, causing them to retain heat.

Cutaway Model of Earth Cutaway Model of Earth
A Piece of Mars on Earth A Piece of Mars on Earth
The movement of water vapor molecules exerts vapor pressure on surfaces. The movement of water vapor molecules exerts vapor pressure on surfaces.
Ocean water is layered from top to bottom Ocean water is layered from top to bottom
Water Molecule Water Molecule
At 34.5°C, oxygen gas expands from 34.5 L to 45.7 L against a constant pressure of 750 mmHg. ... At 34.5°C, oxygen gas expands from 34.5 L to 45.7 L against a constant pressure of 750 mmHg. ...
Video: Functional zones in a mitochondrion

For a complete list of videos, visit our video library