Which would least likely be a cause of natural selection?

Hey me with this one❤☺❤ how do you say that a cell also has a life span and death like an organism? give one example.

Step 1 review the imaginary strand of dna below. note the complementary base pairs. a g c a a t c c g t c t t g g t c g t t a g g c a g a a c c step 2 to begin replicating this strand of dna, draw the two sides of the strand separating. step 3 now, draw the free-floating bases linking up with the separate sides. remember to follow the rules of complementary base pairing. step 4 draw the two resulting dna strands.

What is the next step in the process after a substrate enters the active site of an enzyme