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.
Is red eyes in flies dominant or recessive?
All unmutated flies have red eyes, so orange eyes indicate a mutation in the gene that make red pigment. This mutation is
recessive
and on the sex chromosome, meaning that males and females have different numbers of copies of this gene.
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.
Are sepia eyes dominant in fruit flies?
Brown and sepia eyes are a result of a
recessive gene
and only occur when two sepia-eyed flies mate.
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 fruit flies eyes red?
There are actually two types of pigment in the eye of the fruit fly. The first kind is a rusty-colored pigment called ommachrome pigment. The second is
the reddish pigment, called pteridine
, which gives the eye its bright red color. … The result is clearer vision for the fly.
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 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.
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
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.
Are Wings dominant in fruit flies?
In fruit flies, the
dominant V allele produces long wings
, whereas the recessive v allele produces vestigial wings.
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 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.
Is there any chance that any female offspring might have white eyes?
None of the male or female offspring will have white eyes
.
