HEREDITY
MULTIPLE ALLELES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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X R X r
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X R X R
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Xr X r
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X r Y
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X R Y
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Detailed explanation-1: -In this example, there are two different alleles for the eye color gene: the E allele for red eye color, and the e allele for brown eye color. The red (E) phenotype is dominant to the brown (e) phenotype, so heterozygous flies with the genotype Ee will have red eyes.
Detailed explanation-2: -The genotype of the female offspring would be Xw+Xw because all the female offspring would receive one non-wild type allele from the female parent and one wild type allele from the male parent. Thus, all the female offspring would be heterozygous with red eye color.
Detailed explanation-3: -Females are XX, and males are XY. Sex-linked traits are only found on the X chromosome, therefore the letters are placed as superscripts (above) the X chromosome. Therefore the genotype for the female fly is XrXr and the male is XRY.
Detailed explanation-4: -There are two different genotypes that code for the red-eyed phenotype (XRXR, XRXr) in females. Males have one genotype that codes for red eyes, XRY. Thus, the Red-eyed Male’s genotype can be determined from its phenotype. However, this is not possible in females.