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Alexandra [31]
3 years ago
14

aa. Aa. AA. Zebra mussels have the following genotypes and phenotypes. Which cross would produce the greatest number of heterozy

gous. A) AA x aa. B) Aa x Aa. C) AA x AA. D) as x Aa
Biology
1 answer:
lyudmila [28]3 years ago
7 0

Answer: A (AA x aa)

Explanation:

In option (A) both of the parent mussels are homozygotes, for alleles "a" and "A" respectively. Therefore, every single one (100%) of their offspring would be expected to be Aa heterozygotes. Combinations (B) and (D) yield a lower proportion of heterozygotes (50%), and combination (C) yields none at all. Punnett squares follow:

(A)

<u>   |  A      A        </u>

<u>a |  aA    aA      </u>

<u>a |  aA    aA      </u>

<u />

(B)

<u>   |  A      a       </u>

<u>A |  AA   Aa     </u>

<u>a |  aA    aa      </u>

<u />

(C)

<u>   |   A      A        </u>

<u>A |  AA    AA     </u>

<u>A |  AA    AA     </u>

<u />

(D)

<u>   |  A      a        </u>

<u>a |  aA    aa       </u>

<u>a |  aA    aa      </u>

<u />

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