## Genetic Question help?

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

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lyte22
Garter
Posts: 2
Joined: Wed Feb 22, 2012 5:43 pm

### Genetic Question help?

Hi i've been trying to work this question out but i'm getting kinda stuck..

The kernel on a cob can either be purple (dominant colour) or yellow (reccesive colour) or pink (intermediate colour). The colour purple is the product of a two step reaction with Pink being the intermediate product. You counted kernels on F2 cobs.

Questions:
1) How many purple Kernel would you expect to find
2) How many Pink Kernel would you expect to find
3) How many Yellow Kernel would you expect to find?
4) What colour would be the double homozygous recessive cob?
5) What colour would the F1 cob be?

JackBean
Inland Taipan
Posts: 5694
Joined: Mon Sep 14, 2009 7:12 pm
1-3) from 0 to 100% unless you tell us more info, we can hardly guess

4) what is your opinion? That is not that hard, is it?

5) as 1-3
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

lyte22
Garter
Posts: 2
Joined: Wed Feb 22, 2012 5:43 pm
Lmao i forgot to the numbers!

its 1600 kernels on the F2 cob

For the answers 1-5 i could choose:
900, 800, yellow, pink and purple, purple, 300, 100 and 400

JackBean
Inland Taipan
Posts: 5694
Joined: Mon Sep 14, 2009 7:12 pm
?
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

girlie21
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Posts: 4
Joined: Thu Feb 23, 2012 12:12 pm

### Re: Genetic Question help?

I KNOW I'VE BEEN ALSO STUCK ON EXACTLY THE SAME QUESTION!!
1. How many purple kernel would you expect to find?
2. How many pink kernel would you expect to find?
3. How many yellow kernel would you expect to find?
4. What colour would the double homozygous recessive cob be
5. What colour would the F1 cob be
900
800
100
PINK AND PURPLE
PINK
400
yellow
300
purple

JackBean
Inland Taipan
Posts: 5694
Joined: Mon Sep 14, 2009 7:12 pm
that's nice we know number of F2, but unless you tell us more about parents, we still can hardly guess
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

sudeepa
Garter
Posts: 1
Joined: Thu Mar 01, 2012 3:54 am

### Re: Genetic Question help?

There are two options either Dominant epistasis with ratio 12:3:1 or Recessive epistasis with ratio 9:3:4.

According to the options given it is Recessive epistasis. the ans are

1. How many purple kernel would you expect to find?
Ans. 900
2. How many pink kernel would you expect to find?
Ans. 300
3. How many yellow kernel would you expect to find?
Ans. 400
4. What colour would the double homozygous recessive cob be?
Ans. Yellow
5. What colour would the F1 cob be?
Ans. Purple

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