Question

You also examine the inheritance of feather texture (rough or silky) and feather color (brown or white). You know that neither of these traits is sex-linked. You do the following cross:

a pure breeding male with rough white feathers X
a pure breeding female with silky brown feathers
The F1 chickens have rough brown feathers
Use the upper case letter for the allele associated with the dominant phenotype and the lower case letter for the allele associated with the recessive phenotype. Texture: rough or silky, use the notation T or t. Color: brown or white use the notation C or c.

Answer 1

What is the genotype of the pure-breeding male with rough white feathers?



ii) What is the genotype of the pure-breeding female with silky brown feathers?



iii) What is the genotype of an F1 chicken with rough brown feathers?

Answer 2

n this case, just by looking at the parents, you don't know which traits are dominant and which are recessive. What you do know is that both parents are pure breeding. This means that whatever the case, they have the same alleles for each trait.

For example, the dad has two alleles that make his feathers white, and two alleles that make his feathers rough. Whereas Mom has two alleles for brown feathers, and two alleles for smooth feathers.

Because they will pass one of these alleles on to each offspring, you know that the offspring will have two *different* alleles for each trait.

It will have one allele for white feathers from Dad, and one allele for brown feathers from Mom. And with respect to smooth/rough, it will have one alllele for rough feathers from Dad, and one allele for smooth feathers from Mom. So they will all be heterozygotes.

And they will all express whichever of the two alleles is dominant.

Answer 3

Please ask if that lengthy explanation is unclear to you. :)

Answer 4

i understand perfectly what your explanation is saying... i knew it the confusing part is whether to use Tt or Cc

Answer 5

i an an idea as to what the answers may be but ijust wanted to make sure i was certain

Answer 6

OK, so I really not comfortable giving people answers directly - but if you want to post what you think the correct answer is, I will happily confirm for you whether it is correct or not.

Answer 7

ok i will message you in your inbox

Answer 8

:)

Answer 9

You are running into trouble with the parents genotypes. You know that they are pure breeding for each trait. That means that they have the same allele, for each trait.

For example, Dad could be TTCC, TTcc, ttCC or ttcc. Even though you don't know based on his genotype alone which is dominant (so capital or lower case), you *do* know that for each allele, the capital or lower case will be the same.

Answer 10

Is that much clear? If it is, we will work through Mom next.

Answer 11

And you know that Mom is also pure breeding. So her alleles for each gene are the same, too.

But she looks exactly the opposite of Dad, so whatever alleles Dad has, Mom has the different ones.

For example, if Dad is CC for color, then Mom is cc. Or if Dad is cc, Mom is CC. You don't know which one of them is uppercase or lowercase, but you do know that both their alleles are opposite.

Answer 12

ok well i believe dad is TTcc and mom is ttCC and the F1 is TtCc

Answer 13

The F1 is TtCc. Which means that the dominant trait is expressed, in the offspring. So brown is C and white is c. While rough is T and smooth is t.

So Dad was TTcc and Mom is ttCC. I agree. :)

Answer 14

thanks..... u helped me so much i appreciate it.... just had it all mixed up... cause what i told myself is that the F1 got the rough from the dad so it had to be dominant T and got the brown from mom so it had to be C

Answer 15

You are welcome, and thanks for having the patience to work through the problem.

Answer 16

thanks