When crossing an organism that is homozygous recessive for a single trait (aa) with a heterozygote (aa), what is the chance of producing an offspring with the homozygous recessive phenotype?

50%

Explanation:

if homozygous recessive for a single trait (aa) cross with heterozygote (Aa)

i.e Aa ×  aa

there F1 offspring will be:

the test cross is show below

           A          a

a          Aa        aa

a          Aa         aa

=(Aa, Aa, aa, aa)

the results shows 50% heterozygote and 50% homozygous recessive phenotype.

chlorophyll a: this is the most abundant pigment in plants. chlorophyll a absorbs light with wavelengths of 430nm(blue) and 662nm(red). it reflects green light strongly so it appears green to us.

the father in the first generation probably had the recessive colorblind trait in his x chromosome. if he and his wife both had the colorblind trait, even if she had 1 recessive and 1 dominant, then that trait would be passed on to their kids.

(since you didn't attach the family tree this is just an assumption)