What do the base pairing rules have to do with replication

Why was the sample heated in step 5? describe the chemical principles involved in the reasoning behind this step?

{answer found. it's (3 ) }which statement describes the cell cycle? (1)the cell cycle is a process in which one cell divides into four genetically different cells. (2)the cell cycle is a process in which one cell divides into two genetically different cells. (3)the cell cycle is a process in which one cell divides into two genetically identical cells. (4)the cell cycle is a process in which one cell divides into four genetically identical cells.

What function does the limb sever in each animal? how are the limb bones of the four animals similar? based on these similarities what can be inferred about the evolution of the four animals.