A white-eyed female fruit fly is crossed with a red-eyed male. Red eyes are dominant , and X-linked. What are the expected phenotypes of the offspring? All of the females will have red eyes; half of the males will have red eyes, and half of the males will have white eyes.
Why are red eyes dominant in fruit flies?
Like humans, Drosophila males have an XY chromosome pair, and females are XX. In flies, the wild-type eye color is red (X W ) and it is dominant to white eye color (X w ) (Figure 1). Because of the location of the eye-color gene, reciprocal crosses do not produce the same offspring ratios .
Are red eyes or brown eyes dominant in fruit flies?
In fruit flies, red eyes are dominant to green eyes .
Are red eyes recessive in fruit flies?
Like the orange eyed flies, these flies have normal eye sight, but one of the genes responsible for producing the wild-type red eyes is defective. This mutation is recessive and makes the fly blind. These flies have a mutation that makes it so the body is not instructed to make eyes during development.
Is fruit fly eye color dominant or recessive?
In fruit flies, the wild-type eye color is red (X W ) and is dominant to white eye color (X w ) . Because this eye-color gene is located on the X chromosome only, reciprocal crosses do not produce the same offspring ratios.
Why can’t female fruit flies have white eyes?
This is a clear demonstration of sex-linked inheritance. The eye color gene is located on the X chromosome (one of the sex determining chromosomes of Drosophila). White eye color is recessive . When a red eyed male mates with white eyed females, their daughters will have red eyes, but their sons will have white eyes.
Why are white eyed female fruit flies so rare in nature?
White eyes are very rare in natural fruit fly populations. ... Morgan realized that in these flies, eye color must somehow be tied to sex . From this and other evidence, Morgan deduced that the gene involved in this inheritance pattern is located only on the X chromosome. There is no corresponding eye color locus on the Y.
What happens when you cross a white-eyed female fruit fly with a red-eyed male fruit fly?
A white-eyed female fruit fly is crossed with a red-eyed male. Red eyes are dominant, and X-linked. What are the expected phenotypes of the offspring? All of the females will have red eyes; half of the males will have red eyes, and half of the males will have white eyes.
What color is a fruit fly?
Color: Dull tan to brownish yellow or brownish black ; eyes usually bright red. Larvae are nearly white, except mouth hooks which are black and the tips of the abdominal breathing pores which are yellowish.
Is wild type dominant in fruit flies?
In Drosophila, the most common form is called the ‘ wild type ‘. A mutant can be either dominant or recessive to the wild type. ... If the mutant is recessive to the wild type, its name is given in lower-case, but if it is dominant, it is given in upper case.
Why do some fruit flies have white eyes?
They have a defect in their “white” gene , which normally produces the red pigments in the eye. In these flies, the white gene only works partially, producing fewer red pigments than it should. These flies have white eyes.
What is the genotype of a female fruit fly?
Since the female fly has a yellow body, and the tan body color is the dominant allele
How do you rid of fruit flies?
- Clean all surfaces. ...
- Throw out too-ripe or rotting produce. ...
- Use apple cider vinegar. ...
- Mix apple cider vinegar and dish soap. ...
- Try beer or wine. ...
- Try a chemical fruit-fly spray.
What does a female fruit fly need for white eyes?
1. In fruit flies, the gene for white eyes is sex-linked recessive . (R) is red and (r) is white. Cross a white- eyed female with a normal red-eyed male.
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.
Why do fruit flies have different eye colors?
Some fruit flies bred in the wild have red eyes . Brown and sepia eyes are a result of a recessive gene and only occur when two sepia-eyed flies mate. ... The white-eyed fruit fly gene is recessive and typically is eliminated after mating with dominant-eyed fruit flies for two generations.
