Consider the cross AaBbCcddEe X AABBccDDEe. If these 5 allele pairs all assort independently, then the probability that any individual offspring will have the genotype AABBccDdEe is 1 out of

Question

What will be an ideal response?

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
· What key words does the question contain?

Gather Content

Consider Possibilities
· What other information is related to the question? Which information is most useful?

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

16

Clarify Question
· What is the key concept addressed by the question?
        o This question addresses the probability of a genotype composed of five independently assorting alleles.
· What type of thinking is required?
        o You need to Apply what you know about probability and independent assortment to determine the probability of the given genotype.
· What key words does the question contain?
        o The five genes assort independently – so the result for one gene does not affect the other genes.

Gather Content
        o What do you already know about probabilities?
        o The total probability of a combination genotype is just the individual probabilities multiplied together.

Consider Possibilities
· What other information is related to the question? Which information is most useful?
        o You will need to treat each gene as its own cross to figure out the individual probabilities.
        o For Aa x AA, the outcome AA is 1 of the 2 possible categories of offspring, so its probability is ½.
        o For Bb x BB, the outcome BB is 1 of the 2 possible categories of offspring, so its probability is ½.
        o For Cc x cc, the outcome cc is 1 of the 2 possible categories of offspring, so its probability is ½.
        o For dd x DD, the outcome Dd is actually the only possible category, so its probability is 1.
        o For Ee x Ee, the outcome Ee is 2 of the 4 possible categories of offspring, so its probability is 2/4 or ½.

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o It is important to realize that you must multiply the individual probabilities.
        o ½ x ½ x ½ x 1 x ½ = 1/16

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o This question required you to Apply your knowledge and understanding to this unfamiliar situation.
        o Do you understand why you must multiply the individual gene probabilities?
        o Consider that the first gene is assorted to produce AA in a given cell. The second gene may assort to be either BB or Bb in that cell, so only ½ the time will that AA cell also have BB. Then the next gene again has only a ½ chance of assorting as cc.
        o As you add genes, the combined probability of a specific genotype outcome shrinks.