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Fire-breathing Lizards

APBIO-GELNW5

A fictional lizard population has a gene called Fire1. The dominant allele of this gene allows the lizard to produce a combustion reaction from glands in the back of their throat. A second gene, Fire2, codes for a protein that suppresses the expression of the Fire1 gene.

The lizard population is not fire-breathing, but genetic analysis reveals that a majority of the lizards have at least one copy of the dominant Fire1 allele.

Which of the following would be expected if a mutagen that targets the Fire2 gene was released into the lizard's environment?

A

Genetic variation will decrease as new mutations occur.

B

Phenotypic variation will decrease as the frequency of fire breathing lizards decrease.

C

Phenotypic variation will increase as some lizards will express the fire breathing trait.

D

Variation will not change because any mutations that occur will not affect the Fire1 gene.