nexttttt (4 Viewers)

[AvieT]

But the total one is just a rise of 0.7 degree! How can it kill anything? Or is it a typo they made and it should be 0.7/decade instead?

OK, should I give two possible scenarios that Aus has increased or decreased temperatures?

i think its 0.7 a decade, which when added up ( remember its 1901-2001 ( i think) so thats like.....heaps) it can make a difference to something. shouldnt this question have been poused in like 1901? hahahaha....still dont know if im right.

i just looked at your question, and i think australia would have warmed. my bad, its 0.07, but thats still a considerable amount.

 

[bekmay]

Do we have allocated space for the option? In past exams It's all been just writing booklets. I'm not sure how it would work for all the different options .

ahh wooops sorry thought you were talking about the 8 marker in the normal part =D

uhh welll i guess just do what that person S forget who it was) suggested, 7 marks = roughly 7 points. and include what you think is relevant. i mean just because you might know something partially related to the question doesn't mean it should be added... if you get my drift. but if you're like me and half the time can't even think up 7 things, WAFFLE! ahah

 

[bekmay]

What experiments did Beadle and Tatum use to derive the 'one gene-one polypeptide' theory?

cos i don't have a clue! my textbook's explaination is too complex for me to be bothered understanding. suggestions people?

 

[dolbinau]

What experiments did Beadle and Tatum use to derive the 'one gene-one polypeptide' theory?

cos i don't have a clue! my textbook's explaination is too complex for me to be bothered understanding. suggestions people?

Beadle and Tatum exposed strains of pink bread mould to x-rays. These caused mutations where some strains were unable to produce specific amino acids. (Growth inhibited unless a specific amino acid was in agar plate). They crossed the mutated strains with wild strains to prove the gene could be transfered genetically. They concluded that a gene was responsible for the production of one protein. (However this was changed to one gene-one polypeptide)..

(If I remember correctly)

 

[Undermyskin]

Er.... hope I can word it right this time.

OK, they exposed Red Bread Mould to X-ray that caused them to mutate.
Preparing normal plates with basic nutrients and put these moulds in.
Dispose of the one that grow as normal (because that means they didn't mutate) and keep those that couldn't grow.
Set up different plates with addition of proteins that the normal moulds produced for normal growth. They saw that different moulds grew in different combinations with an addition of different proteins.
Must mention that they knew the mutation induced was only in one specific site of the chromosome.
So they concluded that one gene-one protein theory.

Later from research and knowledge, scientists changed it into one gene one polypeptide due to the fact: many proteins are made up of more than one polypeptide.

 

[AvieT]

What experiments did Beadle and Tatum use to derive the 'one gene-one polypeptide' theory?

cos i don't have a clue! my textbook's explaination is too complex for me to be bothered understanding. suggestions people?

• they grew some mould on bread,
• they exposed the mould to x-rays to mutate it ( theyre killers)
• the x rays killed off some of the DNA in the mould
• the mould was then extracted and put onto new bread, or whatever. heres where it gets a bit tripy.
• if the mould grew, it was THROWN OUT, but if it DIDNT GROW, IT WAS KEPT.
• they then hyopthesised that the mould didnt grow because the xrays had killed some enzymes- possibly the enzymes that made growth.
• they found that if the (x-man) mould was supplemented with other amino acids, it could grow healthily
• they then worked out that one gene codes for one enzyme.
• this was changed to one gene one polypeptied, because "genes code for many protiens that are not enzymes".

and thats it. i THINK it makes sense hahaha. if you ask me, beadle and tatum were a bit..... :rofl:

EDIT: my bad, "then then hypothesised that the mould didnt grow because the xrays had killed some GENES- possible the genes that made growth"
i hope thats right now...

 

[imqt]

thats a pretty clear demonstration, thanks.

hey i finished studying and looking over my notes LOL

SAME but for some reason i still dont feel ready =(

 

[Undermyskin]

LOLZ. You were nearly an awesome mad scientist but you mentioned 'kill enzymes' (what the?).

 

[gloworm14]

SAME but for some reason i still dont feel ready =(

i know, i felt like i kind of got everything while i was reading the notes.
but now looking at questions i actually find it hard to remember everything lol.
oh well.

 

[ugotmegood]

can someone please help with this question...

Describe how modern molecular biology may alter the information transferred from one generation to the next. (4 marks)

Is it genetic engineering/gene cloning??


thanks
x

 

[boony3]

Aviet, i was given a booklet with a whole lot of past questions and that was in there..my teacher went through it a while ago but i forget what he said haha
ohwell lets just hope it aint in the exam (just like im hoping most things wont be im so screwed woooop)

 

[boony3]

if you people havent figured i the dumb kid around here, i just ask all the questions and ask for help.....so i better keep my tradition going and ask about DNA replication......brief summary...what the whole go with mRna and tRna and all that jazzz

 

[bekmay]

• they grew some mould on bread,
• they exposed the mould to x-rays to mutate it ( theyre killers)
• the x rays killed off some of the DNA in the mould
• the mould was then extracted and put onto new bread, or whatever. heres where it gets a bit tripy.
• if the mould grew, it was THROWN OUT, but if it DIDNT GROW, IT WAS KEPT.
• they then hyopthesised that the mould didnt grow because the xrays had killed some enzymes- possibly the enzymes that made growth.
• they found that if the (x-man) mould was supplemented with other amino acids, it could grow healthily
• they then worked out that one gene codes for one enzyme.
• this was changed to one gene one polypeptied, because "genes code for many protiens that are not enzymes".

and thats it. i THINK it makes sense hahaha. if you ask me, beadle and tatum were a bit..... :rofl:

EDIT: my bad, "then then hypothesised that the mould didnt grow because the xrays had killed some GENES- possible the genes that made growth"
i hope thats right now...

HAHAH LOL thanks. and thanks dolbinau and undermyskin. nice work i'm glad you could make sense of it all.

 

[Undermyskin]

Technically, it's genetic engineering, specifically transgenic species.

It modifies the genome of a species by adding a foreign gene from another species. To be a transgenic organism, however, this one must: exhibit the trait + able to reproduce.

e.g. Bt cotton to resist insects, sheeps with plant's gene to resist glowflies, tomato with fish gene to have longer shelf life, red colour, etc.

Probably need a bit of technical knowledge: restriction enzyme cuts out the desired piece of DNA; same enzyme cuts open the DNA of the surrogate gene; the two are mixed with ligase to form a recombinant DNA; it's then inserted into cells by virus (bacteriophages), bacteria (bacterium tumfaciens), microinjection, gene gun, etc.

 

[AvieT]

can someone please help with this question...

Describe how modern molecular biology may alter the information transferred from one generation to the next. (4 marks)

Is it genetic engineering/gene cloning??


thanks
x

i take it that this is like a core topic question? cause i dont really recall learning it about it...but... id say that

• with like cloning or genetic engineering, it reduces genetic variation, and makes the species more sepecptable to diseases
• because of the picking and choosing which information, certian variants within the species will be "bread out" by the genetically modyfied ones.

again, off the top of my head... ..kinda hahaha

 

[Jt2008]

Great posts everyone, really helpful with revising.

Heres one:

Explain TWO changes in the chemical composition of blood as it moves along a capillary. 3 marks

Peace out and good luck tomorrow! Yew:wave:

 

[imqt]

if you people havent figured i the dumb kid around here, i just ask all the questions and ask for help.....so i better keep my tradition going and ask about DNA replication......brief summary...what the whole go with mRna and tRna and all that jazzz

this is all you really need to know FOR PROTEIN SYNTHESIS (according to my teacher

DNA unwinds


mRNA transcribes the amino acid sequences of the bases


mRNA moves out of nucleus to ribosomes


Here tRNA translates the amino acid sequence as indicated by mRNA


tRNA assembles amino acids


Polypetide chain is created and moves back into nucleus




GUYS WHAT ARE THE DIFFERENCES BETWEEN DNA REPLICATION AND PROTEIN SYNTHESIS? like purpose, wheres its made etc

 

[dolbinau]

if you people havent figured i the dumb kid around here, i just ask all the questions and ask for help.....so i better keep my tradition going and ask about DNA replication......brief summary...what the whole go with mRna and tRna and all that jazzz

DNA replication is different from polypeptide synthesis (mRNA, tRNA)

For DNA replication, enzymes cause DNA to unzip; corresponding nucleotides from the nucleoplasm match the unpaired bases by the enzyme DNA Polymerase. Two identical DNA strands are formed.

 

[bekmay]

if you people havent figured i the dumb kid around here, i just ask all the questions and ask for help.....so i better keep my tradition going and ask about DNA replication......brief summary...what the whole go with mRna and tRna and all that jazzz

you mean protein synthesis?

DNA replication=the double helix unzipping and new base pairs being added to create two ladders
transcription and translation=mRNA travelling from the nucleus (where DNA was transcipted) to the cytoplasm where ribosomes act as the 'factory' for the translation process, and tRNA bring the anticodons and amino acids to create polypeptides, thus proteins, enzymes or hormones.

which you talking bout??

 

[AvieT]

Great posts everyone, really helpful with revising.

Heres one:

Explain TWO changes in the chemical composition of blood as it moves along a capillary. 3 marks

Peace out and good luck tomorrow! Yew:wave:

everything is off the top of my head......*idiot*

• as blood moves along the capillary it looses oxygen
• picks up carbon dioxide.
• .......................................................i think thats it??
• LOL if you really wanted to, you could talk about what would happen if the capillary got cut, and then blood came out...

so yeah thoes are the two, i think.