Darwin Carpet Possible Hets. (pics)

[AntaresiaLady]

it means one likes to sleep for the winter, and the other is very shy.

LOL!!

 

[peterjohnson64]

I would except the system stuffs up my matrix. But remember. if little x is recessice and bix X is dominant and you put them together then you get a big X. The only way to get little x is when you have two of them. so XX, Xx and xX looks like X and only xx looks like x.

Lets say blue eyes is "x" and brown eyes is "X". you can only have blue or brown eyes. a person with Xx or xX alleles will have brown eyes but they carry the blue gene so to speak. XX means brown eyes with no blue in them. xx means blue eyes with no brown,.

 

[peterjohnson64]

wow my spelling is immaculate tonight isn't it!!!

 

[SnakeWrangler]

its not easy.
firstly what exactly do you want to know?

I am not sure what I want to know because I don't have any idea what these terms refer to in relation to genetics...

Are these terms related to how the trait is passed to offspring?

 

[Thor1]

the terms dominant and recessive just refer to the genes an animal carries
all carry 2 kind of the way we all have half our chromosomes from one parent an
half from the other. i think thats right.

 

[Thor1]

im not really an expert or anything but i did pass my genetics exam about a month ago

 

[SnakeWrangler]

Here is what I am thinking:

All living things have 2 alleles associated with each trait (eye color, hair color, etc...), one of these alleles is passed from the father and the other from the mother (ok so far?). One of these alleles will be active (does this mean dominant?) and the other will not (does this mean recessive?).

So a dominant allele will be shown in the offspring and the recessive allele will not...

 

[Thor1]

so far so good except both can be dominant or recessive.
dominant alleles always show in the offspring.

 

[Hickson]

Genetics at 2am................I must be bored.

In dominant mutations the matrix pete has been refering to still works, it's just that when you get a het (i.e. Xx) the defective allele expresses itself, so it looks like xx.

So, to use an example, if the presence of the defective allele x produces pink snakes, and the normal colour is brown (and X is normal allele), then:

XX = brown
Xx = pink
xx = pink

Your hets will be pink, the same as the homozygous recessives.



Hix

 

[SnakeWrangler]

So what happens when both are dominant? Is the result a mixture of the two?

 

[SnakeWrangler]

Genetics at 2am................I must be bored.

In dominant mutations the matrix pete has been refering to still works, it's just that when you get a het (i.e. Xx) the defective allele expresses itself, so it looks like xx.

So, to use an example, if the presence of the defective allele x produces pink snakes, and the normal colour is brown (and X is normal allele), then:

XX = brown
Xx = pink
xx = pink

Your hets will be pink, the same as the homozygous recessives.



Hix

Doesn't this mean that het for albino would look albino?


Actually don't worry I get it now.

 

[Thor1]

Hix are you saying the X normal allele is recessive?

 

[Sdaji]

Each gene can have any number of alleles. Many genes only have one allele, so everyone is the same. Many different alleles result in the same phenotype, so they are phenotypically silent. At a given locus, you may be Nn, I may be SS, or you may be Ss and I may be QL etc etc.

You get one copy of every gene from your mother and one from your father. One, the other or both may be expressed.

Alleles can only be 'dominant' against other particular alleles. Brown hair may be dominant to blonde, but black may be dominant to brown (in a situation like this, you'd expect black to be dominant to blonde, but this situation doesn't always exist).

 

[Thor1]

Sdaji please dont bring in locuses.

 

[Sdaji]

Sdaji please dont bring in locuses.

It's loci

 

[Thor1]

ok then please please please dont bring in loci.
thats one part of genetics that i really didnt enjoy.

 

[SnakeWrangler]

So what is a locus? :lol:

Nah, I think this discussion is getting way too complicated to learn over an internet forum, I do feel that I have a better understanding so thanks to everyone for contributing.

Although, I will hang around to hear more if you guys keep going.

 

[Sdaji]

What word do you use instead of loci? I think gene is often used as a substitute for it.

"Gene" seems to be the wildcard when discussing genetics, it can mean just about anything :lol:

'locus' is a very simple concept, if you're going to go on with genetics you'll need to understand it. PM me if you like, I should be able to explain it to you quickly and painlessly. Why didn't you enjoy it? Basically, a locus is just a point on a chromosome where a gene sits.

 

[Thor1]

we had a lecturer who was from europe and i mean no offense to people from over there but
his english needed improvement. that probably didnt help

 

[SnakeWrangler]

So what is a chromosome and how does a gene sit on it? :lol:

You can PM the explanation to me if you like, or maybe recommend some good sites online where it is explained.