In fruit flies bristle shape is found to be incompletely dom

In fruit flies, bristle shape is found to be incompletely dominant with wild being homozygous (++), mild being heterozygous (+b) and bent bristled flies being homozygous (bb). For eye color, orange is dominant over wild in a simple Mendelian fashion.

Assume that two mild bristled, oranged eyed flies (standard F1 cross) are mated, how many of their 720 progeny would you expect to be bent bristled, orange eyed?

Solution

In fruit flies, bristle shape is found to be incompletely dominant with wild being homozygous (++), mild being heterozygous (+b) and bent bristled flies being homozygous (bb).

For eye color, orange is dominant over wild in a simple Mendelian fashion.

Assume that two mild bristled, oranged eyed flies (standard F1 cross) are mated, how many of their 720 progeny would you expect to be bent bristled, orange eyed?

Assume that two mild bristled, oranged eyed flies (standard F1 cross) are mated,

how many of their 720 progeny would you expect to be bent bristled, orange eyed

homozygous (++)

mild being heterozygous (+b)

and

bent bristled flies being homozygous (bb).

R allele --------Dominant –orange color

mild bristled, oranged eyed flies x mild bristled, oranged eyed flies

           Bb Rr X Bb Rr

BR

Br

b R

b r

BR

BR BR

Br BR

BR b R

BR b r

Br

BR Br

Br Br

Br b R

Br b r

b R

BR

Br b R

b R b R

bent bristled

oranged eyed flies

b r b R

bent bristled

oranged eyed flies

b r

BR b r

Br b r

b R b r

bent bristled

oranged eyed flies

b r b r

bent bristled

Answer

Ratio of bent bristled, orange eyed =3/16

=number of bent bristled, orange eyed =(3/16)* 720=135---answer