Question

question 18 of 25

in banded snails, shell color is controlled by a gene with a dominant allele for brown color, \\(b\\), and a recessive allele for yellow color, \\(b\\). the presence of bands is controlled by a gene with a dominant allele that produces no bands, \\(u\\), and a recessive allele that produces five bands, \\(u\\). the two genes do not occur on the same chromosome. snails with the following genotypes are crossed:

\\(bbuu \times bbuu\\)

what is the probability that the offspring will have the \\(bbuu\\) genotype?

a. 0.25
b. 0.00
c. 0.50
d. 1.00

Explanation:

Analyze the parental genotypes

Using the Dihybrid Cross knowledge point

$$ \text{Parent 1: } BBUU \quad \times \quad \text{Parent 2: } Bbuu $$

Determine allele segregation for the B gene

Using the Independent Assortment knowledge point

$$
LATEXBLOCK0
$$

Determine allele segregation for the U gene

Using the Independent Assortment knowledge point

$$
LATEXBLOCK1
$$

Calculate the probability of the BBUU genotype

Using the Independent Assortment and Dihybrid Cross knowledge points

$$
LATEXBLOCK2
$$

Answer:

• A. 0.25
• B. 0.00 (Correct answer)
• C. 0.50
• D. 1.00