Genetics help.

[xsorifc28]

hello everyone. im only 14, and pretty much dont kno anything about genetics.

i have a couple of questions i need help on.

1. DdxDd 3/4 Normal wings, 1/4 dumpy wings.

parentts are both heterozygous. 123 offspring, 88 normal, 35 dumpy wings. (75 to 25 %)

2.if a dumpy winged female is crossed with her father, how many normal-winged flies will be expected among 80 offspring? thx anyone..

[Hades]

i find it hard to believe this question is a freshman biology question. the answer is 40.

 

cross Dd x dd and the resulting cross is 50%

[xsorifc28]

help!?

[xsorifc28]

i find it hard to believe this question is a freshman biology question. the answer is 40.

 

cross Dd x dd and the resulting cross is 50%

 

but then you could cross DD x dd and say the answer is 80...how can you back up your answer?

[CharonY]

The parents are not homozygous.

 

parentts are both heterozygous

[SCIGENIUS]

CharonY is right, if the parents were homozygous the cross would be DDxDD.

Then the resulting offspring would have been 123 out of 123.