This topic contains a solution. Click here to go to the answer

Author Question: During which time period were dinosaurs most abundant?[br][br][b][color=black]Question ... (Read 13 times)

sjones

  • Hero Member
  • *****
  • Posts: 520
During which time period were dinosaurs most abundant?

Question 2

Why werent plants the first form of life to appear on earth?



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

bubulittle310@msn.cn

  • Sr. Member
  • ****
  • Posts: 281
Answer to Question 1

Dinosaurs were most abundant during the Jurassic period, 180135 million years ago.

Answer to Question 2

Some 2.2 billion years ago, free oxygen was present in the atmosphere. Living things used this reactive substance,
not decaying plant material, in biochemical functions of their cells. The free oxygen in the atmosphere also
produced a layer of ozone, which filters out the ultraviolet light from the sun that is harmful to life.





 

Did you know?

Malaria was not eliminated in the United States until 1951. The term eliminated means that no new cases arise in a country for 3 years.

Did you know?

The longest a person has survived after a heart transplant is 24 years.

Did you know?

People often find it difficult to accept the idea that bacteria can be beneficial and improve health. Lactic acid bacteria are good, and when eaten, these bacteria improve health and increase longevity. These bacteria included in foods such as yogurt.

Did you know?

Hippocrates noted that blood separates into four differently colored liquids when removed from the body and examined: a pure red liquid mixed with white liquid material with a yellow-colored froth at the top and a black substance that settles underneath; he named these the four humors (for blood, phlegm, yellow bile, and black bile).

Did you know?

Dogs have been used in studies to detect various cancers in human subjects. They have been trained to sniff breath samples from humans that were collected by having them breathe into special tubes. These people included 55 lung cancer patients, 31 breast cancer patients, and 83 cancer-free patients. The dogs detected 54 of the 55 lung cancer patients as having cancer, detected 28 of the 31 breast cancer patients, and gave only three false-positive results (detecting cancer in people who didn't have it).

For a complete list of videos, visit our video library