USA Biology Olympiad (USABO) Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Prepare for the USA Biology Olympiad with engaging flashcards and multiple choice questions. Each question is accompanied by hints and detailed explanations. Ace your exam with confidence!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

What is the probability of obtaining the genotype AAbbCCdd from the parents AaBbCcDd and AABbCcDd, assuming independent assortment of all gene pairs?

1/32
1/64
1/128
1/256

The correct answer is: 1/128

To find the probability of obtaining the genotype AAbbCCdd from the parents AaBbCcDd and AABbCcDd, we can analyze each gene independently, since the genes assort independently. 1. **For the A allele**: - Parent 1 (Aa) can contribute either A or a with a probability of 1/2 for each. - Parent 2 (AA) can only contribute A with a probability of 1. - Therefore, the probability of getting an A from the first parent and an a from the second parent to produce the genotype Aa is 1/2 for A from the first parent and 1 for A from the second parent, resulting in a probability of 1/2. 2. **For the B allele**: - Parent 1 (Bb) can contribute either B or b with a probability of 1/2 for each. - Parent 2 (Bb) can also contribute either B or b with a probability of 1/2 for each. - To get the genotype Bb, we can obtain it from B (from either parent) and b (from the other). The possible combinations that yield Bb are: - B from Parent