What is the genotype for a purebred fly with white eyes?

Why is the White-eyed characteristic more common in males?

Since males have only one copy of each sex chromosome, they are hemizygous for all sex-linked genes, and they always express the phenotype * of the allele * they get. As a recessive trait, the white eye phenotype is masked by the presence of a wild-type (red encoding) allele.

What is the genotypic ratio of white-eyed Drosophila?

Crossing the red-eyed F1 males and females produces a 3:1 F2 ratio of red-eyed to white-eyed flies, but all the white-eyed flies are males. This inheritance pattern is explained by the alleles being located on the differential region of the X chromosome; in other words, by X-linkage.

What is the chance that the offspring will have white eyes?

What is the chance that there will be an offspring with white eyes? 50% or 244 Page 2 6. Hemophilia is a disease caused by a gene found on the X chromosome. Therefore, it is referred to as a sex-linked disease.

Why must males inherit colorblindness from their mothers?

Why must males inherit colorblindness or hemophilia from their mothers? Because their mother gives them their X chromosome. Why is colorblindness or hemophilia more common in males than in females? Because the trait is recessive and since they only have one allele, there is no Other allele expressed.

Which Cross would most likely produce 50% white-eyed males and 50% red-eyed males?

Crosses between true breeding white-eyed females and red-eyed males would result in 50% red-eyed females and 50% white-eyed males because the white eye trait is linked to the X-chromosome and males only inherit their X chromosome from their mother.

Why are few characteristics in humans y linked?

Why are few characteristics in humans Y-linked? The presence of the Y chromosome determines the male sex, while the absence of the Y chromosome determines the female sex.

What is the genotype of a white eyed female fly?

Genotypes and phenotypes of offspring if the female is heterozygous. Half of the male and half of the female offspring of a heterozygous female would be white-eyed; the other half would be red-eyed. Therefore the female must be a heterozygous, Xw+ Xw.

Is sepia eye color in Drosophila recessive?

The fruit fly Drosophila melanogaster possesses disproportionately large, often vividly colored eyes. Brown and sepia eyes are a result of a recessive gene and only occur when two sepia-eyed flies mate. White, vermillion and cinnabar-eyed fruit flies result from mutations and are far less common.

Can a man be heterozygous?

If B is the allele for baldness and b is the allele for normal hair, a bald man can be heterozygous (Bb) or homozygous bald (BB). A man with normal hair must be homozygous normal (bb). A normal woman can be homozygous normal (bb) or heterozygous (Bb).

Are humans homozygous or heterozygous?

Since humans possess two copies of each chromosome, they also have two copies of each gene and locus on those chromosomes. Each of these trait-encoding genes (or loci) is called an allele. If the alleles are different, the person is heterozygous for that trait.

What is the heterozygous trait?

Heterozygous refers to having different alleles for a particular trait. When alleles are heterozygous in complete dominance inheritance, one allele is dominant and the other is recessive. The genotypic ratio in a heterozygous cross where one parent is heterozygous and the other is homozygous for a trait is 1:1.

What is meant by heterozygous?

Heterozygous refers to having inherited different forms of a particular gene from each parent. A heterozygous genotype stands in contrast to a homozygous genotype, where an individual inherits identical forms of a particular gene from each parent.

What does a heterozygous genotype look like?

The genotype might look like BB for two dominant alleles or bb for recessive alleles. The other possible combination is heterozygous, which means the genotype contains one of each allele, such as Bb. Just try to remember that hetero- means different, and homo- means the same.

Which genes are dominant?

Dominant refers to the relationship between two versions of a gene. Individuals receive two versions of each gene, known as alleles, from each parent. If the alleles of a gene are different, one allele will be expressed; it is the dominant gene. The effect of the other allele, called recessive, is masked.