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Gamete distribution and offsprings from select matings

1) Consider a genetic locus that could hold either of the alleles P or p (where P is dominant, p is recessive). Consider a second genetic locus (for some other unrelated trait) that could hold either of the alleles R or r. Listed below are some genotypes of individuals for each of these loci:

a) PPRR b) PpRR c) ppRr d) PpRr

For each of these genotypes, assume that the two loci assort independently of each other (2nd law). Figure out what different kinds of gametes they could form.

2) Consider again the loci Pp and Rr. Individuals with the following genotypes are mated to each other:

a) PpRR X PPRr b) PpRr X pprr c) PPRR X ppRR d) PpRr X PpRr

Assume again, that P alleles assort independently of R alleles. Figure out what all possible genotypes are for the offspring of each mating, and at what frequency each of the genotypes would appear among the offspring. (ex: PPrr is 1/16 of offspring)

Submit your responses using the following format:

1. a) (list gametes on one line with commas)

b) (as above)

c) (as above)

d) (as above)

2. a) genotype #1, frequency

genotype #2, frequency

etc.

b) as above

c) as above

d) as above

Solution Preview

1) For the given genotypes we must figure out what gametes are possible. Assuming random assortment of these independent alleles the possibilities are as ...

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