Darwin Carpet Possible Hets. (pics)

[Sdaji]

Hehe, I had a few lecturers who pronounced it strangely. There's always the big divide between "lock-us" and "low-cus" people. I'm definately a "low-cus" person and can't help but think strange thoughts about the others :lol: The "lock-us" lecturers used to drive me mad!

 

[Thor1]

Sdaji thats one for you.
my brain is slowing down from lack of sleep.

 

[SnakeWrangler]

Well i'm off to bed, thanks again guys for taking the time (especially at this hideous hour) to explain this stuff, it has been very enlightening to say the least, you guys have inspired me to want to learn more about it...

Cheers

 

[Hickson]

This is where semantics get into it.

The normal allele is described as Normal. It is neither a dominant nor a recessive allele.

However, it is dominant over a recessive allele in that it expresses itself.

If you have a defective allele that is Dominant, then it expresses itself over the normal allele which then appears to be recessive.

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?).

You are correct up to the last sentence - the word 'active' is not really accurate in this context. If the two alleles are identical, they will be expressed jointly. If the alleles are different, then the one which is dominant over the other will express itself.

The reason 'active' is not a good word to use here is because there are some genes that are 'switched on' or 'switched off' at certain times. They can be called active when they are 'switched on'. Furthermore, there are genes which act as switches, they become active and produce hormones which inturn switch on other genes. When the switch stops producing the hormone, the second gene switches off.

It's all rather complex. Wait til we start discussing polymorphism, crossing over and jumping genes!



Hix

 

[Hickson]

Bugger! I dozed off writing the above post and Sdaji answered the question, then everyone went to bed.

Maybe I should take the hint and follow suit.



Hix

 

[Sdaji]

DNA (well, nuclear DNA, the stuff which, generally speaking, people are talking about when they talk about genetics) is arranged on chromosomes. Imagine you have a paired set of pieces of string. Say, eight pieces of string, two of them are 4cm long, two are 5cm long, two are 6.5cm long and two are 12cm long (all arbitrary). The two sets are essentially identical, you got one from mum and one from dad. These pieces of string don't really do anything, they are just a framework you can stick important stuff on to. Imagine now that the pieces of string have knots along them. The pairs have the knots in the same place. Okay, now imaging that at each knot there is a note which says something like "green eyes", "tall", "short", "smart", "freckles" etc etc. If you line the pairs of string up, each knot will be next to a knot in it's homologous partner. Now look at the notes, you might find a pair which says "Short" "Short", in which case you'd be a short person. Another pair might say "idiot" "genius", in which case you'd either be an idiot (if idiot was dominant to genius), a genius (if genius was dominant to idiot), somewhere in between (if they were codominant) or, perhaps, you might be an insane genius, if the affect was additive (this is a bit advanced and certainly way beyond the layman, I won't get into it further).

So, the strings are chromosomes, the knots are loci and the notes are genes. It doesn't matter what the note says, if it's at the same place as another note, they're the same gene. An allele is a different type of note/gene. (A height locus ('knot') might have four alleles - pygmy, short, tall, giant).

Within a species, every individual has the same number of pieces of string with the same number of knots in the same places. Every knot always has a note.

Generally, we hideously oversimplify and what I've described is only a tiny amount of what is going on. We generally only discuss Mendelian genetics, which only represent a small percentage of the traits we're interested in (height, intelligence, how yellow a jungle carpet is, whether or not a Black headed python will eat mice, etc etc are not Mendelian and the situation is far more complex).

Before anyone points it out, yes, I deliberately left out sex chromosomes, there are gene duplications, I know I oversimplified, there are haploids and polyploids, etc etc etc.

2.40am is probably not the best time to be explaining this I'll probably read it in the morning and think "string, knots and notes" what on earth? :shock:

:lol:

 

[Hickson]

I'll probably read it in the morning and think "string, knots and notes" what on earth? :shock:

:lol:

For anyone else whose thinking "what on Earth?", let me say that, at this time of the morning, it's a pretty damn good attempt at explaining the intracies of one of the more difficult biological subjects.



Hix

 

[Sdaji]

I'll probably read it in the morning and think "string, knots and notes" what on earth? :shock:

:lol:

For anyone else whose thinking "what on Earth?", let me say that, at this time of the morning, it's a pretty damn good attempt at explaining the intracies of one of the more difficult biological subjects.



Hix

Well, you're using 3am judgement :lol: It did seem reasonable to me while I typed it, but it might be a bit less clear and perhaps misleading to people who don't already understand it.

I'd better hit the sack before I make too many more typos

 

[Slateman]

ok ok so in dumb alby terms if i get one snake carrying the dominant gene and one carrying the recessive gene do we get albino babies :idea: :shock:

Breed two animals who carry the same recessive gene for albino, and you will produce a certain ratio of albinos, Hets, and non albino gene carrying offspring.

Het = Xx

Albino = xx

Normal =XX

So breed Hets
Xx + Xx
=

Xx ,XX, xx
(the above result is the % of each type produced, just the types of offspring from the pairing example)
Matt

(Edited: to make a "little" more sense)

This explanation was good enough for old Slateman to get it. Must be clear for anybody now.

 

[waruikazi]

Good to see you finally got them Matt! Odin has an awesome dorsal stripe on him, put us down for some hatchies when they arrive.

That explanation is not entirely accurate Matt, (i couldn't bother to read the whole htread so if this has been said apologies) if you breed het to het and we represent albino gene with X and non albino gene with x so the snakes dna could be represented as Xx you would end up with the following...

25% Xx
25% xX
25% xx and
25% XX

With albinism being a redessive trait this means you will end up with 50% het, 25% without albino gene and 25% albino.

 

[Hickson]

Waruikazi,

Go and read the whole thread, that has been covered, and X means the non-albino allele, whereas x represents albino.



Hix

 

[Australis]

Good to see you finally got them Matt! Odin has an awesome dorsal stripe on him, put us down for some hatchies when they arrive.

That explanation is not entirely accurate Matt, (i couldn't bother to read the whole htread so if this has been said apologies) if you breed het to het and we represent albino gene with X and non albino gene with x so the snakes dna could be represented as Xx you would end up with the following...

25% Xx
25% xX
25% xx and
25% XX

With albinism being a redessive trait this means you will end up with 50% het, 25% without albino gene and 25% albino.

Its was very early in the morning, but even after editing my post, i still left a typo, i "wasnt" trying to give any % of what the offspring would be, just a basic idea of what you could get from one example of a pairing.

Yeah, i Love the dorsal striped one, i will try and get a female to match that fella.



Matt

 

[waruikazi]

That explanation is not entirely accurate Matt, (i couldn't bother to read the whole htread so if this has been said apologies) .

 

[Australis]

That explanation is not entirely accurate Matt, (i couldn't bother to read the whole htread so if this has been said apologies) .

Dam.. i didnt read your whole post either.


Matt

 

[waruikazi]

LOL it happens

 

[Stevo]

Here is an adult of mine with similar markings

 

[Australis]

Very nice Stevo,

Just what i wanted to see

Cheers
Matt