biology question

sissybaby

Super Member
Registered
Joined
Jan 22, 2008
Messages
2,699
Reaction score
626
Location
somewhere, out there
Hello, everyone

If this is a repeat, I apologize, but I think I lost my connection while typing in my question.

I think I remember way back 100 years ago, in biology class, we determined that two blue-eyed people could not produce a brown-eyed child. We used a little chromozome chart, and I need to know what that thing was called?

Would appreciate anyone's expertise on this, and if I'm wrong about the eye color thing, please let me know that, too.

Thanks so much.

Sissy
 

Mr Flibble

They've been very bad, Mr Flibble
Kind Benefactor
Super Member
Registered
Joined
Jan 6, 2008
Messages
18,889
Reaction score
5,029
Location
We couldn't possibly do that. Who'd clear up the m
Website
francisknightbooks.co.uk
Blue eyes are recessive, whilst brown eyes are dominant.

So two blue eyed people cannot have the brown eye gene to pass it on ( or they wouldn't be blue eyed, they'd be brown eyed).

However it is possible for two brown eyed people to hav a blue eyed child -- if they both have one recessive blue gene and one dominant brown gene

Mendel's punnett chart is probably what you are thinking of ( he used it for sweet peas) here

Capitol B = dominant, small b = recessive. All those with the capital( even just one) will exhibit the dominant gene, only the bb will show the recessive characteristic

If you have any type of dominant gene, it will take precendence, although the recessive can be passed on
 
Last edited:

giusti

Super Member
Registered
Joined
Mar 8, 2008
Messages
302
Reaction score
25
Location
Baboonistan
This theorem can also be used when determining which disorders and other afflictions can skip a generation, and which ones must have a direct tie to a parent.

-giusti
 

sissybaby

Super Member
Registered
Joined
Jan 22, 2008
Messages
2,699
Reaction score
626
Location
somewhere, out there
Thanks IRU - just can't type that name you've chosen! and Giusti, you've both been very helpful. I just didn't want to come across as a total nincompoop if I was wrong by some chance.

Sorry, IRU - your avatar reminds me so much of my niece - that's her attitude totally!
 

mommyjo2

Bad grammar make me [sic]
Super Member
Registered
Joined
Oct 18, 2006
Messages
455
Reaction score
53
Location
Houston
Website
www.milehimama.com
However, two blue eyed people CAN have a green or hazel eyed child. The "true blue" recessive gene tends to be concentrated in peoples of Scandinavian and Norwegian descent. (There is more than one blue eye gene)
 

Melanie Nilles

What're you looking at?
Super Member
Registered
Joined
Oct 14, 2006
Messages
369
Reaction score
26
Location
USA
Website
www.melanienilles.com
The chart is called a Punnet Square. And it's true that unless there's a mutation, two blue-eyed people can only produce blue-eyed children, because blue is recessive to brown.

This might help: http://www.athro.com/evo/gen/punnett.html

Edit: Ooh! and there's a link to more about human eye color examples if you scroll down to the bottom ;)
 
Last edited:

GeorgeK

ever seeking
Super Member
Registered
Joined
Jul 17, 2007
Messages
6,577
Reaction score
740
There are at least 8 genes identified having to do with human eye color and that does not include the effects of epigenetics which can really play with your sense of understanding it all. The more we learn, the more we realize that we really don't know. There are several shades of "blue" or relative "blueness". Although it is very unlikely that 2 blue eyed people will have a brown / brownish eyed child it is not an iron clad lack of paternity suit. For undergrad biology your books will say that it can't happen, but in higher level study you will find that almost nothing is impossible; unlikely, yes, but not impossible.