Question

In fruit flies, the allele for white eyes is recessive to the allele for red eyes. In a generation of fruit flies, 45 males with white eyes, 46 females with white eyes, 44 males with red eyes, and 47 females with red eyes are produced. Which of the following is the best conclusion you can make about the parents of this generation?

One parent was heterozygous for eye color and the other was homozygous with red eyes.

Both parents were homozygous with red eyes.

One parent had white eyes and the other was heterozygous for eye color.

Both parents were heterozygous for eye color.

Answer 1

Hey Andrea, it helps us help you if you if you also explain what part of the question you would like help with, or how you'd go about starting it...

Answer 2

I don´t understand the homozygous, heterozygous stuff

Answer 3

OK, heterozygous / homozygous refers to whether both alleles for a gene are the same. The organism is homozygous if both alleles are the same - that is, either both are dominant or both are recessive. The organism is heterozygous if the alleles are different - that is, if one allele is dominant and the other allele is recessive...

Answer 4

If you decided to call the allele for eye color w, where a lower case w indicates the recessive, white eyed phenotype and a capital W indicates dominant, red eyed phenotype then:

homozygous genotypes: WW and ww
heterozygous genotypes: Ww

Hopefully that's helpful. :D

Answer 5

So let's say I give you the possible genotypes: WW, Ww and ww. Do you know what phenotypes (appearance) each genotype will have?

Answer 6

as in hetero or homo?

Answer 7

homo, hetero, homo

Answer 8

Yes. The WW is homozygous (homozygous dominant), the Ww is heterozygous and the ww is homozygous (homozygous recessive).

I asked you if you can interpret those genotypes. What color eyes will the WW flies have? What about the Ww and ww flies?

Remember that we have said W (red) is dominant to w (white)...

Answer 9

Would you prefer it if I did WW as an example?

Answer 10

is the answer a?

Answer 11

A is technically correct, but there is a better, more specific answer...

Answer 12

C?

Answer 13

Why do you think C?

Answer 14

bc the offspring had mixed eye color and B and C are for one

Answer 15

i mean B and D

Answer 16

OK, C is correct.

But I am really concerned that you don't understand why it is correct. You have posted quite a few questions over the last couple days (there is certainly nothing wrong with that!!!) but I am concerned that you are getting answers without becoming clearer about why those answers are true. Speaking a tutor, that is a problem. :/

From a scientific perspective, do you know why C is correct? If not, would you like me to work through the problem with you so you do understand it?

Answer 17

yes please

Answer 18

So genotypes are actual genetic make up of an individual - what alleles it has. In this case there is one gene and two different alleles of it so there are three possible genotypes: WW, Ww and ww.

Corresponding to each genotype is a phenotype, or appearance.

For example, if the fly has even a single dominant allele, big W, it will have a dominant phenotype. In this case, a dominant phenotype corresponds to red eyes. So for example, a WW fly will have red eyes, as will a Ww fly.

Can you tell me what sort of eyes (red or white) a ww fly will have?

Answer 19

You can look at it this way: Does a ww fly have a dominant allele?