Genetics -Help!?

1- A normally pigmented man marries an albino woman. They have 3 children, 1 is albino.What is the Genotype of the father?





2- 2 intensely freckled parents have 5 children,2 that are intensely freckled 3 that aren't. (Assume the trait is governed by a single pair of alleles), is the intense freckledness an example of dominant or recessive inheritance, Why?





3-Epistasis Problem:





a- A male black Labrador retriever of genotype BbCc mates with a female Labrador retriever of genotype BbCc. What color can their offspring be?


b- In what % is each of them expected to occur? (use a dihybrid cross to answer)


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1- I think it's heterozygous b/c there are Different alleles involved,but Idk how to set up the Punnett Square to prove it is it PP x pp?





2- I know it's dominant b/c both parents are freckled but IDK how to prove that.





3- I just have no idea where to start.How do I set the punnett square up etc?





Please Help Me Understand How to do these!Thank You! = )

Genetics -Help!?
1. The father is heterozygous. Use these in the punnet square:


Aa x aa. (The father is the heterozygous one, the mother is the homozygous)





2. You're right. It is a dominant inheritence. To prove that just use these in a punnet square: Ff x Ff Those show that both parents have freckles because it is dominant. But if you do the punnet square on that, you will see that there is a 25% chance that the offspring will not be freckled. (there is a "ff" in one of the squares) That is where the unfreckled kids came from.





3. Okay, this one is kind of tricky to explain through words over the computer. But, you take your BbCc x BbCc and it kind of like "foiling it." I don't know if you are familiar with the term "foil" but it is used in math. First you set up a dihybrid cross. (i assume you know what that is, 16 squares total.) Take your first term: BbCc. Along the top of the punnet square do this:





1st block: BC


2nd block: Bc


3rd block: bC


4th blcok: bc





Now take your second term and do the exact same thing since both terms are the same. Now all you have to do is cross them. I don't know what to tell you about what color their offspring can be because you didn't tell me what the "Cc" trait is for. But to find out the percent is easy. Just take how ever many blacks you get and divide it by 16 since there are a total of 16 blocks.





I hope this helped you. I took Genetics last year. E-mail me back at bhuff89@yahoo.com and let me know how everything went.

survey research