A. In guinea pigs, black fur is dominant over white fur.
- A homozygous male is mated with a white female.

How would I set up the parent genotypes?

Question

A. In guinea pigs, black fur is dominant over white fur.
- A homozygous male is mated with a white female. 

How would I set up the parent genotypes?

karatechopper · Answer

For the female I say, bb
For the male is it going to also be bb or BB?

anonymous · Answer

BB

karatechopper · Answer

How do I know? Like how do you for sure know its BB

aaronq · Answer

if in the question is says that he is homozygous dominant then it's BB for sure.

homo = same

homozygous = 2 of the same alleles

karatechopper · Answer

I agree with what you say, but the question does not specify

aaronq · Answer

it doesn't specify if the male is black homozygous?

i mean it would be a pretty boring exercise if the male was homozygous recessive

you have a bb X bb cross which would give you all bb offspring

karatechopper · Answer

Nope it doesn't specify..

aaronq · Answer

hm i would assume it's homozygous dominant simply because you'd have a bb X bb cross otherwise.

anonymous · Answer

hey can u help me with my question i posted ? @aaronq

karatechopper · Answer

Alright, thank you both!!x

aaronq · Answer

no problem, dude !

karatechopper · Answer

Now wait hold on..
A homozygous male is mated with a white female. Find:
A. genotypes of each parent (I have set them for BB and bb)
B. Genotype and Phenotype for F1 generation (I crossed the parents, got Bb for each, there fore I set up the F1 generation as Bb x Bb. Now I have ended up with  1 BB, 2 Bb, 1 bb.

So genotypes/phenotypes are
BB/black fur
Bb/black fur
bb/white fur

C. genotype and phenotype for F2 generation (How do I set this one up?)
@aaronq

shrutipande9 · Answer

the set that u got 1BB 2Bb 1bb is the f2 generation...u have also written the genotype...

shrutipande9 · Answer

parent-BBxbb
f1-Bb
f2-1BB 2Bb 1bb

karatechopper · Answer

Don't you have to cross it all tho?

shrutipande9 · Answer

u have already crossed 2 people of f1 generation...so the result of this cross is f2...u need not cross it again...

karatechopper · Answer

oh ok

shrutipande9 · Answer

and i guess if they havent specified the phenotype of male u need 2 consider both the homozygous genotypes...
bbxbb and BBxbb

karatechopper · Answer

hm ok.

aaronq · Answer

sorry i had to go but seems like you got things resolved.