Two species of flies, Drosophila melanogaster and Drosophila simulans, can mate. They usually do not mate, however, even if they
1 answer:
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Answer:
a.
b.
c.
d.
e.
Explanation:
There are two sex chromosomes, X and Y. A female has two X chromosomes and the male has an X and a Y. The genotype then for male and female woud be:
Female = XX
Male = XY
Now the superscript indicates the allele for a particular trait.
Based on what was given:
H is dominant (no hemophilia)
h is recessive (hemophilic)
B is dominant (no color blindness)
b is recessive (color blind)
As you can see in the given, the Y chromosome has no allele, this means that hemophilia and color-blindness is X-linked or dependent on the X chromosome.
For the first, it says normal male this means that the genotype would be XY , the X chromosome would have the normal dominant allele for color-blindness so that would be B.
The next one would be homozygous normal female. This means that the female has both dominant alleles on their chromosome (BB)
The third one says colorblind male. Unlike the females, the male chromosomes only need the X to be affected for them to express the trait. So in this case, the X will have the recessive allele for colorblindness (b).
The foruth one is a normal female for color-blindess but is heterozygous. This means that the female has the recessive allele, but the dominant trait masks it. So it will have both alleles (Bb)
Lastly, a color-blind female would have to have two recessive alleles. This is what we call homozygous recessive (bb).