Allele for gray fur is A (dominant)
Allele for white fur is a (recessive)
Genotype of heterozygous is Aa (heterozygous is gray, because its allele is dominant)
If we cross two heterozygous
<span>Parents: Aa x Aa
</span> <span>F1: AA Aa Aa aa</span>
The ratio between phenotypes is 3:1 (gray:white)
<span>AA Aa Aa are with gray fur</span>
<span>aa is with white fur </span>
<span>Others are external fertilization:
</span>a. all of the sperm will fertilize eggs.
b. sperm and egg will be released simultaneously.
c. the number of sperm and eggs produced will be equal.
<span>e. sperm will be protected until they can unite with the eggs.</span>
The answer is Nitrogen fixation
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