What is Drosophila mutant?
They have a defect in their “curly gene,” which is on the second chromosome. Having curled wings is a dominant mutation, which means that only one copy of the gene has to be altered to produce the defect. In fact, if both copies are mutated, the flies do not survive. Normal Fruit Flies.
Are Drosophila males hemizygous?
Males are said to be hemizygous, because they have only one allele for any X-linked characteristic. Drosophila males lack a second allele copy on the Y chromosome; that is, their genotype can only be XWY or XwY. In contrast, females have two allele copies of this gene and can be XWXW, XWXw, or XwXw.
Are Drosophila males haploid?
Normally, flies have either one or two X chromosomes and two sets of autosomes. If there is but one X chromosome in a diploid cell (1X:2A), the fly is male. If there are two X chromosomes in a diploid cell (2X:2A), the fly is female (Bridges 1921, 1925). Thus, XO Drosophila are sterile males.
Why are Drosophila males hemizygous?
Males are said to be hemizygous because they have only one allele for any X-linked characteristic; males will exhibit the trait of any gene on the X-chromosome regardless of dominance and recessiveness. Most sex-linked traits are actually X-linked, such as eye color in Drosophila or color blindness in humans.
What is the difference between male and female Drosophila?
The most simple characteristic to use to differentiate the two is to look at the genitalia of the flies. Males have dark, rounded genitalia at the tip of their abdomen, whereas females have light, pointed genitalia. Male Drosophila are generally smaller than their female counterparts, and have a darker abdomen.
What is the genotype of the male?
Male Genotype When a sperm carrying the Y chromosome fertilizes an egg, the resulting embryo has a genotype of XY and will be a male. With rare exceptions, all other embryos will be XX or female. Although the Y chromosome codes for a male, the X chromosome is vital for normal human development.
Are males heterozygous or homozygous?
Whatever allele the male fly inherits for an X-linked gene will determine his appearance, because he has no other gene copy—even if the allele is recessive in females. Rather than homozygous or heterozygous, males are said to be hemizygous for X-linked genes.
How do you tell a fly’s gender?
Look at the color of the abdomen. A fly’s abdomen is made up of many different segments. On a male fly, the last two segments of the abdomen are much darker than the female. The males have thick black bands, whereas the females tend to have one darker band on the bottom with a lighter band on top of that.
What are the differences between male and female Drosophila Class 12?
Male Heterogamety includes human males having XY sex chromosomes and males of some insects having XO sex chromosome. Female Heterogamety includes the females of some species of birds, fishes, and insects. In Drosophila, males are heterogametic.
Why must parental female flies be virgins when setting up the initial crosses?
Virgin flies are needed to make sure that that the crosses are being appropriately made with the females using the desired sperms to fertilize their eggs. Female Drosophila are considered virgin eight to ten hours after they hatch from their pupa because during that time they are not receptive to male companionship and …
Do male fruit flies eat?
In addition to finding out that food- and sex-deprived male fruit flies choose eating over mating, the team also learned that this clear preference for food over sex happens more notably after 15 hours of starvation.