## Alberta Free Tutoring And Homework Help For Biology 30

0

Help

### A pure breeding yellow bird is mated with a pure breeding blue bird. There is a lack of dominance in feather colours and all offspring are green feathered. What are the correct genotypes of a green bird, yellow bird, and blue bird, respectively? Select one: a. BY, YY, and BB b. By, yy and BB c. Yb, YY and bb d. Bb, bb and BB

5 months ago

The correct option is c. This is the example of incomplete dominance. Here yellow colour (YY) is incomplete dominant to blue (bb)

5 months ago

When we're looking at genes that code for a particular trait, we use one letter to represent that trait. In this case, we have a gene for feather color which we will use the letter BB to represent. We have a pure breeding yellow bird with a genotype of bbbb, and a pure breeding bluebird with a genotype of BBBB. If we put this in a punnet square, with the alleles for the bluebird on the top of the Punnett square and the alleles for the yellow bird on the left of the Punnett square, we get all green offspring.

BB bBbBb bBbBbBB bBbBb bBbBb

The genotype of the green bird is BbBb, the yellow bird is bbbb, and the bluebird is BBBB.

Since answers ab, and d all show a mix of two different genes, the only possible answer would be answer c.

5 months ago