All the offspring of a cross between a black-eyed mendelian and an orange-eyed mendelian have black eyes. what is the expected phenotypic ratio of a cross between two orange-eyed mendelian?

a. 3 black-eyed:1 orange-eyed

b. 0 black-eyed:1 orange-eyed

c. 1 black-eyed:3 orange-eyed

d. 1 black-eyed:0 orange-eyed

Question

Biology

Bianca

23 March, 16:37

All the offspring of a cross between a black-eyed mendelian and an orange-eyed mendelian have black eyes. what is the expected phenotypic ratio of a cross between two orange-eyed mendelian?

a. 3 black-eyed:1 orange-eyed

b. 0 black-eyed:1 orange-eyed

c. 1 black-eyed:3 orange-eyed

d. 1 black-eyed:0 orange-eyed

+2

Answers (1)

Know the Answer?

Enzo Chase · Answer 1

The answer is B. The first cross between the black-eyed mendelian and an orange-eyed mendelian resulted in all of them having black eyes. This means that black-eyed is the dominant trait in the species. That means if a phenotype is orange-eyed then it is homozygous recessive (bb). There will be no black-eyed since all of them are recessive.