According to scientific thought when does one species of organisms become two species

Could someone me with number one you

Which sentence best describes the relationship between chlorophyll and the chloroplast? a.)chlorophyll is a chemical found in a chloroplast. b.) chloroplast is a chemical found in a chlorophyll. c.) both chlorophyll and chloroplasts are found in animals. d.) both chlorophyll and chloroplasts make carbon dioxide.

Asmall population of chimpanzees lives in a habitat thant undergoes no change for a long period of time. how will genetic drift affect this population