In a cross with homozygous dominant and homozygous recessive parents (P-generati
ID: 96751 • Letter: I
Question
In a cross with homozygous dominant and homozygous recessive parents (P-generation), what proportion of the offspring in the F-2 generation (if you self-cross the F-l Generation) would exhibit the phenotypic characteristic of the recessive parent? In a test cross, the individual with the unknown genotype is crossed with an individual with what genotype? In human blood types, which blood type best represents codominance? Which human blood type allele is recessive to two different alleles? In snapdragons the two alleles for flower color belong to one gene and this gene exhibits incomplete dominance. What will be the phenotypes of a cross of a red snapdragon with a white snapdragon?Explanation / Answer
1.Suppose if we choose the character of length the recessive plants will have following genotype-tt and the dominant ,homozygous plants will have following genotype -TT.If we cross them-
TT X tt P
Tt (100%) F1
When Tt is selfed F2 is obtained-
T t
Thus only 25 % of the pants are short having a recessive genotype tt.
2.The organism in question is crossed with an organism that is homozygous for the recessive trait, and the offspring of the test cross are examined.
3.AB Blood group represents Co dominance as A and B both are dominant independently and when they coexist together they are codominant.
4.O is recessive to A and B alleles.
5. R R
F2-
R r
In F2 25% red (RR)
25% white (rr)
50% pink(Rr)
T Tt Tt t Tt tt