Question

Can someone help me with this question I’m not getting it

Answer 1

a.
`X^BY`

b.
`X^BX^B`

c.
`X^(b) Y`

d.
`X^BX^b`

e.
`X^bX^b`

Step-by-step 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.

`X^BY`

The next one would be homozygous normal female. This means that the female has both dominant alleles on their chromosome (BB)

`X^BX^B`

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).

`X^(b) Y`

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)

`X^BX^b`

Lastly, a color-blind female would have to have two recessive alleles. This is what we call homozygous recessive (bb).

`X^bX^b`