Question

A customer brings in some hamsters to a pet store, some have gold fur and some have black fur.The pet store owner has never come across golden fur hamsters and he doesn’t know if gold fur is dominant or recessive to black and he doesn’t know the genotypes of each of the hamsters. He crosses one golden hamster to one black hamster multiple times. They have over 60 babies; all of them have golden fur.

a.From the information above:

i.Is it possible to determine how the trait is inherited? (yes or no)

ii.If so, state which trait is dominant and recessive and in one sentence explain why you came to this conclusion.

iii.Define your alleles for the fur color trait; use the letter F.

b.In the cross described above, what are the genotype(s)of each parent and the babies?

golden parent hamster genotype = ___________ x black parent hamster genotype = ___________F1 golden fur babies genotype(s) = _____________

c.You cross one of the golden F1 hamstersback to theblack parent hamster.

i.What are the genotypes, corresponding phenotypes and phenotypic probabilities of the progeny from the cross?

ii.If they have 7 progeny and all seven progeny are golden:

1.Would this be considered an ordered or unordered event? (circle one)

2.What is the probability all seven progeny are golden?

3.How many possible outcomes are there for all seven progeny are to be golden? ______________________

iii.If they have 7 progeny,and three of the progeny are golden and four are black:

1.Would this be considered an ordered or unordered event? (circle one)

2.What is the probability three of the progeny are golden and four are black?

3.How many possible outcomes are there for three of the progeny are golden and four are black

Answer 1

i)) yes

Based on the information given, we can determine the mode of inheritance

ii) golden fur is dominant and black fur is recessive

Since all the F1 phenotype is golden fur , it mask the expression of black fur and it is dominant

iii) F- golden fur

f- black fur

B) genotype of golden fur hamster - FF

Genotype of black fur hamster - ff

F1 golden fur genotype - Ff

C)

1. Ff * ff

Genotype - Ff, ff

Phenotype - golden fur ( heterozygous) , black fur ( homozygous)

Phenotypic probability

Golden fur - 1/2

Black fur - 1/2

1. Unordered event

2. 0 . All the progenies cannot be golden progenies

3. 0

Iii) 1)ordered

2. There is more than 50 percent probability for 3 golden and four to be black

3. 35 possible outcomes are possible