Genetics Question: genes and ratios ?
If I have a generation of maize cob with a phenotypic ratio of 1:1:1:1 then what would the genotype of the parents be when one of each trait is displayed:
Phenotypes:
Black grains: B
yellow grains: b
smooth grains: S
wrinkled grains: s
observed:
BS = 48
Bs = 45
bS = 44
bs = 43
So parent A & B are…?
I got BbSs for both is this right?
Related posts
-
Genetics help! (10 points)?
Genetics help! (10 points)?
Genetics help! (10 points)?
this is a genetics question?
Is a Japanese diet a good one to go on?
Very small baby refusing to eat?
Question about flax seed?
what color is my foal?
If you were a nut, which type would you be?
How do I lower my LDL when I already have a cholesterol-free diet?
For all the bakers: 3 QUICK questions on SHORTENING?
coconut oil?
going from vegetarian to raw food only question?
2 comments a "Genetics Question: genes and ratios ?"
No, that isn’t correct. If the parents are both hybrids (BbSs), then a cross between two hybrids (a dihybrid cross) would yield a phenotypic ratio of 9:3:3:1 in the offspring (assuming typical dominant and recessive genes). In order to get the phenotypic ratio of 1:1:1:1 in the offspring, then either of two possibilities must occur: 1) one parent must be a homozygous recessive at each locus and the other parent must be heterozygous at each locus, OR 2) one parent is heterozygous at one locus, homozygous recessive at the other locus and the other parent is homzygous at the first locus and heterozygous at the other locus (kind of a mirror image of the other parent):
Possibility 1)
BbSs x bbss
So the possible offspring would be:
BbSs
Bbss
bbSs
bbss
Possibility 2)
Parents:
Bbss x bbSs
offspring:
BbSs
Bbss
bbSs
bbss
Sorry … if both parents are BbSs you’d have a ratio of 9:3:3:1. To get a ratio of 1:1:1:1, one parent is BbSs and the other is bbss.
Post your comment