Biology question? genetics Question? x?

Question

can you answer this?

Using the symbols N= Normal wing and n=short wing, write down the following:

The genotype of a fly which is heterozygous this trait?

the possible genotypes of its gametes?

what kind of offspring would be produced if a heterozygous fly matted with one which was homozygous for normal wing?

help would be appreciated! thanks guys!

Answer 1

1.) Nn

2.) The fly will offer one N and one n to the gametes.

3.) Nn x NN

Use punnett square.

Offspring: NN, NN, Nn, Nn

100% phenotype for normal wing

genotype: 50% homozygous dominant and 50% heterozygous

good luck.  

Answer 2

Heterozygous: Nn (Heterozygous contains both Wild and mutant)

assuming normal split, 50% of the gametes would be N, the other would be n

Consider that each fly will contribute to 50% of the offspring gametes. the easiest way to figure these problems out is by using a punnet square.

__N__n

N NN Nn

N NN Nn

Or possibly more clearly: Nn-->N+n

                                         NN-> N+N

possible combinations are NN or Nn,

  

The offspring would be 50% heterozygous, 50% homozygous Normal.

        

Answer 3

Nn is heterozygous.

Cross with NN (homozygous for normal) you get

NN, Nn, NN. Nn

Answer 4

Heterozygous = Nn.

Gametes  = N (normal wing.) and n = (short wing).

Nn x NN - gives 100% normal  (50% NN(Normal) and 50%Nn(Normal))