Genetic Crossing

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

Moderators: Leonid, amiradm, BioTeam

Post Reply
larock01
Garter
Garter
Posts: 22
Joined: Sat Apr 15, 2006 6:42 pm

Genetic Crossing

Post by larock01 » Sat Apr 15, 2006 9:25 pm

Two rabbits are crossed, both of which have brown fur. In rabbits, brown fur is dominant over white fur. Six of eight offspring produced have brown fur, and the other two have white coats. What is the genotype of the parents?

I am hesitating on the following:

- BBxbb
- BBxBb
- Bbxbb
- BbxBb
- bbxbb

Can anyone help me?
Thanks in advance.

User avatar
LilKim
Coral
Coral
Posts: 436
Joined: Mon Mar 20, 2006 8:36 pm
Contact:

Post by LilKim » Sat Apr 15, 2006 11:23 pm

what do you think the answer is? I don't want to answer it for you... give it a shot .. and we can compare our answers with your answers.

larock01
Garter
Garter
Posts: 22
Joined: Sat Apr 15, 2006 6:42 pm

Post by larock01 » Sun Apr 16, 2006 4:39 pm

I'm thinking choice number two (BBxBb) because more offspring show the dominant trait than the recessive trait.
Can you confirm that?

kiekyon
Coral
Coral
Posts: 410
Joined: Thu Feb 16, 2006 6:10 am
Location: Malaysia

Post by kiekyon » Mon Apr 17, 2006 2:46 am

larock01 wrote:I'm thinking choice number two (BBxBb) because more offspring show the dominant trait than the recessive trait.
Can you confirm that?


nope, BBxBb produce all offspring with dominant traits
:lol: :lol: :lol:

User avatar
LilKim
Coral
Coral
Posts: 436
Joined: Mon Mar 20, 2006 8:36 pm
Contact:

Post by LilKim » Mon Apr 17, 2006 3:21 am

Try drawing it out in punnett squares... I'll give you a hint you'll end up with 2 phenotypes and 3 genotypes. Please let me know if you're still having trouble...

I know you can do it!

Good luck!
- KIM

ajs
Garter
Garter
Posts: 10
Joined: Wed Mar 01, 2006 12:21 pm

Re: Genetic Crossing

Post by ajs » Fri Apr 21, 2006 4:07 pm

larock01 wrote:Two rabbits are crossed, both of which have brown fur. In rabbits, brown fur is dominant over white fur. Six of eight offspring produced have brown fur, and the other TWO HAVE WHITE COATS. What is the genotype of the parents?

I am hesitating on the following:

- BBxbb
- BBxBb
- Bbxbb
- BbxBb
- bbxbb

Can anyone help me?
Thanks in advance.


You don't need to use a punnett square; two have white coats therefore genotype is bb. As the genotype of these two offspring is bb, parents must both have the b allele. Parents both show the dominant allele as a phenotype. Therefore both parents are Bb; ie genotype of both parents is heterozygous

edjopp
Garter
Garter
Posts: 1
Joined: Mon Apr 24, 2006 7:37 am

Post by edjopp » Mon Apr 24, 2006 7:41 am

Can a type O male and a type O female produce a type b offspring (boy)?

Can someone help me?

User avatar
MrMistery
Inland Taipan
Inland Taipan
Posts: 6832
Joined: Thu Mar 03, 2005 10:18 pm
Location: Romania(small and unimportant country)
Contact:

Post by MrMistery » Mon Apr 24, 2006 6:03 pm

If you are reffering to blood types, then you might want to know that type O is homozygous reccesive.. now it should be easy
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest