Need help with a potiental biology test question

[gimpyone]

A peruvian pingobat has two traits: hair and color.  For color: yellow (C) is dominant to white (c).  For hair, an X-linked recessive trait: hairy (H) is dominant to bald (h).  A yellow, bald male pingobat was crossed with a white, hairy female pingobat.  All of the F₁ generation, males and females, were yellow and hairy.  What are the genotypes of the parents?  Demonstrate this cross using a Punnett Square.  What would be the phenotypes and their ratios if two of the yellow, hairy F₁s were crossed?  Again use a Punnett Square to demonstragte the cross.  Remember gender is a phenotype.

Please help me f13, you're my only hope.

[Strazos]

Please bear in mind that I have not stepped inside of a bio lab in more than 6 years. As such, it's entirely possible I am completely wrong.

This is probably more a question for one of the women here, such a VDL or Lantyssa; they both have Bio backgrounds I believe.

But I try, because I love.

[Lantyssa]

The last time I used the squares was ninth grade (I do have exposure to biochemisty, but I am a chemist by training).  Now I have to go read up because this is the geek version of sudoku.

My non-professional partial answer, before reading up, is that the male parent is CC/hh and the female is cc/HH.  Offspring of the second generation will be yellow (CC), yellow (Cc)x2, white (cc).   I think they will all be hairy , but the breakdown I'm not as sure about due to the x-linking (what I need to read up on).

[WayAbvPar]

Yeah. Learned all this 20 years ago (straight As!) and have forgotten pretty much all of it. I still understand the concepts, but the mechanics escape me.

Now I have to go read up because this is the geek version of sudoku.

Heh. I have some folks here at work that are really into sudoku. I would rather use a pen or pencil to gouge out my eyes than do a sudoku, but YMMV.

[Strazos]

Someone come give us the correct answers. 

[Sky]

I also used to be a whiz at this stuff, before I went full-time into music and dumbified myself. I was a straight-A student in all the high school sciences (AP stuff), and my first college major was biochemistry. I was best at chemistry.

I found genetics extremely handy back when I was a teenager growing weed. We had a lot of generational maps done, one of our circle was also a science teacher. Lots of experimentation done to isolate and/or cross traits. Good times. REALLY GOOD TIMES ;)

/sigh being responsible and not wanting to expose myself to stupid drug laws. I miss those days :(

[Lantyssa]

Okie, here is my revised answer:

f0, xx = white, hairy = cc, HH or Hh
f0, xy = yellow, bald = CC or Cc, -h

f1 xx, xy = yellow = CC or Cc
f1 xx = hairy = HH or Hh
f1 xy = hairy = H-

1) The mother was white, she must be cc and all of f1 must have a c.  As none of f1 had white, the father must be CC.
2) The father can only give h to females, no determination for males of f1.
3) For all females of f1 to have hair, the mother must be HH.

f0, xx = white, hairy = cc, HH
f0, xy = yellow, bald = CC, h-

Code:

f0  c  c      H  H
 C Cc Cc  xh Hh Hh
 C Cc Cc  y- H- H-

f1 xx = yellow, hairy = Cc, Hh
f1 xy = yellow, hairy = Cc, H-

Code:

f1  C  c      H  h
 C CC Cc  xH HH Hh
 c Cc cc  y- H- h-

The second generation has three yellow for every one white, for either sex. All females are hairy, males have 50% to be either.

Which confirms what Strazos said.

[Strazos]

Wouldn't the male parent of F0 have to be CC? If he was Cc, with the mother being cc, you'd get a cc (white) child.


But wait....my stupid little chart that I did with MS Paint is actually right?

Heh, I think I bombed the genetics portion of one of my exams when I took AP Bio in High School....but I seem to remember much more involved math.

[WayAbvPar]

Right or wrong, you get bonus points for slapping it together with MS Paint. That was awesome.

[gimpyone]

I didn't do well on the test but I got this part right :D

[voodoolily]

I  Punnett squares. Lantyssa saved the day in my stead, so you go girl.

[Lantyssa]

Wouldn't the male parent of F0 have to be CC? If he was Cc, with the mother being cc, you'd get a cc (white) child.

Yes, but we both said that, so it's all good.

My initial line is what the parents could be based only on the information given.  Points 1-3 narrowed down what the parents had to be.  The two diagrams I made are f0 -> f1 and f1 -> f2, if that is where the confusion was.  I know my labelling was rather poor.

I  Punnett squares. Lantyssa saved the day in my stead, so you go girl.

Thank you.

[gimpyone]

Thank you from me too everyone who helped :)

[OcellotJenkins]

I would rather use a pen or pencil to gouge out my eyes than do a sudoku, but YMMV.

But sudoku improves your pre-frontal cortex!!



(Any other Brain Age addicts in the house? :))

Right or wrong, you get bonus points for slapping it together with MS Paint. That was awesome.

Agreed!

[Sky]

I was kind of interested in Brain Age until I heard it had sudoku, I just don't like them.

[Trippy]

I was kind of interested in Brain Age until I heard it had sudoku, I just don't like them.

The Sudoku part is separate from the rest -- i.e. it's not part of the "Daily Training" program.