Which step of mitosis involves the condensing of dna into chromosomes?

Which of the following is a possible reason for sleep? a) growth b)digestive c)speed d)intelligence

This is one of the five kingdoms in the older biological succession. organisms in this kingdom are prokaryotic

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.