1. what is the word for a type of communication that goes from cell to cell 2. what is the word that means “within the cell,” such as referring to signals moving from one place to another within the cell? 3. explain why multicellularity of an organism requires cell-to-cell communication.

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.