How might life on earth be different today if mass extinctions never occurred ?

Q: a pair of homologous chromosomesa) always has the same genes and the same allows b)always has the same genes c)always has the same alleles d)never has the same genes

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.

Body temperature is tightly regulated in mammals for example when external temperatures drop too much the body of a mammal responds by in order to its core temperature?