What is necessary component of a short story?

What is the central idea in this advice from branch rickey to jackie robinson?  

Plz ! i genetic mutation occurs in a rabbits muscle cell this genetic mutation will be passed on to, a. the existing cells in the rabbits body. b. the cells that are next to the mutant muscle cell. c. cells that are produced when the mutant cell divides. d. the cells of the rabbits offspring.

The triumph of night, toward the end if the story , starting on page 5 faxon encounters a man in furs whta function does fcxons interaction with this character serve?