If you cross a white-eyed female (ww) to a red-eyed male (WY) Drosophila fly, you will see red-eyed females and white-eyed males in the F1 generation. If you cross an F1 red-eyed female to an F1 white-eyed male, what is the approximate percentage of total progeny in the F2 generation that are white-eyed males

25%

Explanation:

ww gives white-eye female

WY gives red-eye male

       ww    x    WY

 F1: Ww   wY   Ww   wY

Ww - red-eye female

wY - white-eye male

Crossing the two F1

           Ww    x    wY

F2: Ww   WY   ww   wY

Remember that white-eye male = wY

Percentage of wY = 1/4 or 25%

Hence, the percentage of progeny in the F2 generation that would be white-eye males = 1/4 or 25%

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.