The mass extinction at the end of the mesozoic era was caused by
a. solar radiation
c. an ice age
b. a meteor or asteroid colliding with earth
d. volcanic activity

In order to study genetic mutations, scientists must study genetic material. which statement describes the genetic material scientists are most likely studying? a) they study alleles that contain chromosomes, which are rna.b) they study alleles that contain genes, which are chromosomes.c) they study chromosomes that contain genes, which are dna segments.