two genetics questions

Genetics as it applies to evolution, molecular biology, and medical aspects.

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
kahle
Garter
Garter
Posts: 3
Joined: Mon Jun 29, 2009 9:10 pm

two genetics questions

Post by kahle » Mon Jun 29, 2009 9:19 pm

What percentage of offspring will be expected to have blood type A if the parents have types AB and O? What percentage will have blood type O? I can do Punnett squares but what is the second allele for blood type O?


Also, a wild-type fruit fly (heterozygous for both body color and eye color) is mated with a fly exhibiting two recessive mutations, ebony body and sepia eye. The offspring distribution is 100 wild body/wild eye, 34 wild body/sepia eye, 30 ebony body/wild eye, and 94 ebony body/wild eye. Are the genes for these two mutations linked or not? Explain.
Why didn't the problem read 124 ebony body/wild eye? Help?

User avatar
canalon
Inland Taipan
Inland Taipan
Posts: 3909
Joined: Thu Feb 03, 2005 2:46 pm
Location: Canada

Post by canalon » Tue Jun 30, 2009 3:45 pm

In the ABO system you have three possible alleles: A, B and O, and each chromosome carry only one allele at a time. A and B are codominant, O is recessive.
You now have everything you need to complete your Punnet square.

What is expected here is a comparison using Chi-square test between the theoretical/expected distribution of the offspring if the characters are independent and what is observed in real life.

Good luck
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)

kahle
Garter
Garter
Posts: 3
Joined: Mon Jun 29, 2009 9:10 pm

Re:

Post by kahle » Tue Jun 30, 2009 6:06 pm

canalon wrote:In the ABO system you have three possible alleles: A, B and O, and each chromosome carry only one allele at a time. A and B are codominant, O is recessive.
You now have everything you need to complete your Punnet square.

What is expected here is a comparison using Chi-square test between the theoretical/expected distribution of the offspring if the characters are independent and what is observed in real life.

Good luck

Thanks! I get it now! 50% blood type A (AO) and 50% blood type B (BO)! Great!
Happily, Kahle

User avatar
Jesse2504
Garter
Garter
Posts: 47
Joined: Mon Jun 01, 2009 4:28 pm

Re: two genetics questions

Post by Jesse2504 » Tue Jun 30, 2009 6:55 pm

This may help visualize it a bit better:

Image
Jesse

I spit in the mouth of a god, who whispers in the minds of the children

"The most incomprehensible thing about the universe is that it is at all comprehensible" - Albert Einstein.

kahle
Garter
Garter
Posts: 3
Joined: Mon Jun 29, 2009 9:10 pm

Re: two genetics questions

Post by kahle » Thu Jul 02, 2009 1:55 pm

Thanks so much! Kahle

Post Reply

Who is online

Users browsing this forum: Google [Bot] and 2 guests