Ethical, social and political.... / One gene, one polypeptide (1 Viewer)

[^___ShabS___^]

does N E 1 have info on any of these dot pnts ????

Please post them..... ive spent a lot of time on these @$#%! dot points....trying to gather info but when i do they r too hard to understand.....

and i dont want to spend n e more time on them....they've taken too much of my time...!!!!??? wanna print them all in this holiday...

1) Analyse information from secondary sources on the historical development of theories of evolution and use available evidence to assess social and political influences on these developments.

2)analyse information from secondary sources to outline the evidence that led to Beadle and Tatums one gene one protein hypothesis and to explain why this was altered to the one gene one polypeptide hypothesis.

3) analyse information from secondary sources to identify examples of the use of transgenic species and use available evidence to debate the ethical issues arising from the development and use of transgenic species.

 

[babydoll_]

1) and 3) you can basically make it up in my opinion. You could talk about religion and stuff, bla bla. Religion is the big one mainly.

2) : genes code for polypeptides, and polypeptides make up protein. Think of it this way:
genes = letters
polypeptides = words
proteins = sentences

So although genes make codes for proteins technically, saying that genes make codes for polypeptides is more accurate.

There is lots of good info on this in t he notes on the main BoredOfStudies website. Hope this helped!

 

[xiao1985]

also, the evidence:

they exposed some bread mould(Neurospora cross) to x ray - mutating it... the mutated bread mould is unable to produce a particular vitamin or amino acid...

conclusion: there is a link between biochemical process and the gene present...


q 1... maybe talk abt the creationism of christianity, and how that ( the dominating explanation of the origin of humanity and everything on earth) is challenged by all the theories suggested by the biologists... (u can talk abt larmark's theory of evolution here, very neatly fits into the picture)

q3 ... yea, basically use ur imagination... mine gives me:
useage: (too many) cure of alot of enzyme deficient diseases (cystic fibrosis, for eg)
ethical issue: animal cruelty
ecologically alienated alleles
accidents => cancer, mutants (uhm, ninja turtles... )
health risk if you talk abt GM food...

 

[t-i-m-m-y]

also, the evidence:

they exposed some bread mould(Neurospora cross) to x ray - mutating it... the mutated bread mould is unable to produce a particular vitamin or amino acid...

conclusion: there is a link between biochemical process and the gene present...

how do u find the time to post all over the place, in bio in tution forums etc..

anywayz what xaio said is correct, i think if my memory serves me right, the neurospora had a arginine production pathway, and a single mutation would affect any given enzyme along that pathway

how could i forget all this i remember archibald garrod in the early 1900's? came up with this idea originally.

okay opening up my bio text reveals this:
-each mutatnt produced by the experiment was analysed and all were found to be defective along the biochemical pathway of synthesis of arginine; so i was right
- using genetic crosees, they found that there were different classes of mutant, each defective in a different gene
- they found some classes of mutants could produce (well actually, keep it simple); various products of the pathway
- the evidence provided strong support for garrods hypothesis

the modification to one-gene-one-polypeptide, came from scientists realising that some proteins are made from multiplde polypeptides eg. hemoglobin

blehz that was a long post. hope it helps

 

[^___ShabS___^]

thanks guys........
got them all.................

 

[xiao1985]

@ timmy : well tis post exam ~~~ tho quite busy, loggin onto bos is like becoming routine work =p

 

[kow_dude]

I still don't get the one gene one polypeptide hypothesis. Why did they expose bread mould to x-ray and how did this mutate it.
From what i'm thinking, the x-ray kills the gene and that is why the moulds can't produce the amino acids.

 

[xiao1985]

x-rays can't physically kill genes as such , as genes are not really alive... the high energy of the x-ray can rearrange the orders of the bases however, causing mutation...

 

[kow_dude]

So what was the point in mutating the moulds? How does it show the 'one gene one protein' hypothesis?
Sorry about this... i find it confusing

 

[babydoll_]

Well say a sequence AAGCAA, that would code for two amino acids (a set of 3 bases -> one amino acid)... which in turn would make part of one polypeptide... was identified

But say, through mutation, a base was removed, e.g. AACAA (removal of a G-base), then the 2nd amino acid will not be programmed for. This proved that certain sequences coded for certain polypeptides... does that make sense?

 

[kow_dude]

Yea it does!
So... the x-ray mutated the genes, and this mutated gene 'stuffs up' the mould's ability to produce a certain animo acid. Hence, the mutated gene would create some other amino acids that it did not intend to make. And this shows that a specific gene would make a specific protein.

Is that right? :S

 

[babydoll_]

Yep, you've got it

 

[kow_dude]

Hmmm i'm confused again... this mould mutation meant that it's now a different specie and therefore produces a different kind of amino-acid. Is that correct?

 

[babydoll_]

No, the mutation creates a different sequence of different bases, which therefore programs a different amino acid, which has a different usage in the mould.

 

[kow_dude]

So all Tatum and Beadle did was mutating genes and observed the amino acids produced?

I read this article which said that they crossed mutated moulds to normal moulds. Is that true?

 

[babydoll_]

1st: basically, and from that they proved the one gene, one polypeptide/protein theory.

2nd question: I'll leave that to t-i-m-m-y or xiao to answer, but I really don't think you need to know that.

 

[t-i-m-m-y]

lets get this straight first;

A mutation is a change in the base sequence of DNA... theres different types of mutations; but only covered in genetics I think

Yes, they did cross mutated moulds and normal moulds, but thats far more detail than u need.

 

[sikofthis]

hey, im doing this assesment on beadle n tatum's hypothesis on tuesdy.. i can't find anything that seems useful anywhere to answer the last few sections we have to research.. plz! can any1 help me!

1: the hypthesis' significance in the establishment of modern techniques

2: the relevance of the discovery of their hypthesis on our understanding of the process of evolution

3revious important scientific works and experiments leading to this hypothosis (Garrod and stuff i think)