What is the ultimate source of genetic variability?

A. Gene flow
B. Mutations
C. Genetic drift
D. Non-random mating

b. mutations

Explanation:

Mutations can alter single nucleotides or entire chromosomes, and they are the sole source of new alleles. The ultimate source of genetic variation is mutation- changes in nucleotide sequences in the DNA.

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.

the answer

b.) bowling ball