Question

) A metallic blue-colored Indian blue peahen with long pinion feathers is crossed with a dull brown-colored Indian blue peacock with short pinion feathers. Half of the resulting peacocks are metallic blue with short pinions and half the resulting peacocks are metallic blue with long pinions. Half of the resulting peahens are dull brown with short pinions and half the peahens are dull brown with long pinions. Long pinions are the result of a functional protein. A) Which gene is sex-linked? B) What are the genotypes of each parent and each type of offspring?

Sorry for the long question but I was told two different ways to this. Which one is correct

First way

Genotypes for parents -

A metallic blue-colored Indian blue peahen with long pinion feathers = BbLl (BL, Bl, bL, bl)

Dull brown-colored Indian blue peacock with short pinion feathers = bbll (bl, bl, bl, bl)

	BL	Bl	bL	bl
bl	BLbl BbLl	Blbl Bbll	bLbl bbLl	blbl bbll

Genotypes for offspring =

Metallic blue with long pionion feathers = BbLl

Metallic blue with short pioion feathers = Bbll

Dull brown with long pionion feathers = bbLl

Dull brown with with short pioion feathers = bbll

Should you include if it is a peahen or peacock?

No genes are sex-linked. It follows Mendel’s Law of Independent Assortment, which says “that separate genes for separate traits are passed independently of one another from parents to offspring.”

Second way - if this is correct how do you do the punnett table and which gene is sex linked.

Another way I was told to do this is

Bull brown (B) is dominant over blue (b)

Long pinion (L) is dominant ove short (l)

Genotypes for parents -

A metallic blue-colored Indian blue peahen with long pinion feathers = xbxb, Ll

Dull brown-colored Indian blue peacock with short pinion feathers = xby, ll

Peahen xbxb, Ll

Peacock xby, ll

Determine whether either of the genes are sex-linked. For this type of a question, if you aren’t told, then the thing for which to look is whether when looking only at the offspring one of the phenotypes sorts out by sex. NOTE: if you are dealing with a species that doesn’t have sex chromosomes (e.g. bees, wasps, most reptiles), you can’t have a sex-linked trait. Are birds reptiles or mammals?

Thank you Please do punnett table and explain what is sex linked gene if the second way is correct. Sorry again for the long post.