Which of the following gases were present in the atmosphere of 4 billion years ago?

A) water

B) methane

C) ammonia

D) all of the above

What material would be best used where water will accumulate? gravel or bedrock

How does this simplification misrepresent what takes place during the process of photosynthesis

If a person has lost a significant amount of blood but still maintains a normal blood pressure it does not necessarily mean that the person is maintaining adequate perfusion.

Which part of cellular respiration uses 2 ATP and produces 4 ATP per glucose molecule

What is the main link between the brain and the rest of the body?

Can natural selection cause new variation?

The first step of biologists takes when deciding how to study life is to___.

If rabbits gave birth to two young every two years, like bears, what would happen?

Genes are located on what and each gene controls a specific what

Refer to the introductory section of the chapter entitled "Earthbound Extraterrestrial? Or Just Another Microbe in the Mud?" Which of the following statements would be a feasiblehypothesis? A. If microbes do not have phosphorus, they will die. B.