Which of the following is not part of the structure of a nucleotide? a. amino acid b. phosphate group c. sugar d. nitrogen base

The process of meiosis produces only gametes, eggs or sperm. according to the diagram, how many sperm are formed from each cell that undergoes meiosis?

Dna replication occurs in preparation for

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.