Question

Answer the next five questions based on the following information. You are studying a particular type of spider and have identified four traits that follow simple mendelian genetics. The B gene governs body color and black body color is dominant to brown. The D gene governs whether or not the spider is poisonous, and poisonous is dominant to non-poisonous. The E gene governs eye color and black eyes are dominant to red eyes. The H gene governs hair type and hairy is dominant to hairless. Indicate your answer numerically not alphabetically. For instance, answer "2" not "two." For each answer that is not a whole number, give your answer as a fraction reduced to the lowest possible whole numbers. For instance, 3/9 would be reduced to 1/3.
How many different types of gametes can be formed by a spider that has the genotype BbDdEeHH?


If you chose a single gamete at random from a spider that has the genotype BbDdEeHh, what is the probability that the gamete would have the genotype BdEh?

You mate a BbDDEeHh spider with a BbDdEEHh spider. What is the probability that one randomly chosen offspring will have the genotype BbDdEEHH?

Answer 1

Answer:

a. 81/256.

b. 9/256.

b. 9 / 256.

Explanation:

The given traits in the question follow the Mendelian character. The cross between the body color where B is responsible for black color and b is responsible for brown color is as follows: Bb × Bb results in the 3/4 black color ( BB, Bb, Bb) and 1/4 brown color progeny (bb). The cross between the poisonous and nonpoisonous trait where D is responsible for poisonous trait and d is responsible for nonpoisonous is as follows: Dd × Dd results in the 3/4 poisonous trait  (DD, Dd, Dd) and 1/4 nonpoisonous (dd). The cross between the eye color where E is responsible for black color and e is responsible for red color is as follows: Ee × Ee results in the 3/4 black color ( EE, Ee, Ee) and 1/4 red color progeny (ee). The cross between the hair trait where H is responsible for hairy and h is responsible for hairless is as follows: Hh × Hh results in the 3/4 hairy (HH, Hh, Hh) and 1/4 hairless (hh).

a. The cross between BbDdEeHh spider with a BbDdEeHh spider results in the 3/4black body, 3/4 black eyes, 3/4, hairy, and 3/4 poisonous progeny. Their probability is 3/4× 3/4× 3/4× 3/4 = 81/ 256.

b. The cross between BbDdEeHh spider with a BbDdEeHh spider results in the  3/4black body, 3/4 black eyes 1/4 hairless, and 1/4 nonpoisonous progeny. Their probability is  3/4× 3/4×1/4 3/4×1/4 = 9/256.

Thus, the answer is a. 81/256.