Which energy-rich compound is formed from organic matter by mixed
biogeochemical processes?

20 the compound al(nh3)2 has atoms of nitrogen.

Which of the following must be true for a fossil organism to be useful as an index fossil? a. the fossil organism must be widespread geographically. b. the fossil organism must be abundant. c. the fossil organism must be limited to a short span of geologic time. d. all of the above.

At the age of 6 months, caleb was diagnosed with tay-sachs disease. as his primary care physician, what would you tell his parents about this disease?