Biologists! How was it?

[annie]

ah i didnt know it was 1 mark, i thought it was worth more than that so im feeling better now.

Also does anyone know what was the right answer to the cell that first initiates the specific immune response??
I wrote macrophages, i had thought of Helper T cells.... then i thought that macrophages display the foreign antigens on its surface
and carry it to the lymph nodes ......

[Marc]

unfortunately i wrote cytotoxic T cells.. oh well.. only 1 mark..

[JL_91]

A few other people and I wrote Th cells

[annie]

Yea Th cells may well be the right answer, theres another mark down the drain.....

i had just thought that antigen presentation was the first step to activating the T Helper cells....

http://en.wikipedia.org/wiki/Antigen_presentation

But it might not be what vcaa wants

[nancy]

1) FOr the use of copper what did ppl write?
2) The first short answer i think where you had to compare and say why the graphs were the same what did ppl write?
3) the interneuron what letter did ppl write/?
4) how did ppl design their experiment>? just curious??/

[yonis_d]

for the interneuron i wrote 't' was that right

[JL_91]

annie, VCAA might be open to different interpretations

1) FOr the use of copper what did ppl write?
2) The first short answer i think where you had to compare and say why the graphs were the same what did ppl write?
3) the interneuron what letter did ppl write/?
4) how did ppl design their experiment>? just curious??/

1) If you mean that question about why it has to be regulated - I put that too much copper may be toxic, while too little can impair the organism's functioning. Or something equally random..
2) I wrote that light is one of the obligatory inputs for photosynthesis, therefore photosynthetic rate, i.e. the rate of output, is much dependent on the input of light...something around those lines.
3) letter T (or whichever one was in the middle, on the spine bit of the diagram)
4) my experimental design involved splitting the mice into 2 groups of 10, one being the control and the other being the experimental group. The control group was left untreated, while the experimental group was treated with a set a mount of vitamin D pills each day over a period of ?? months (forgot what I wrote). Then the rest of it was just observe/record etc., and I said that if the overwhelming majority of mice in the experimental group experienced reduced development of rheumatoid arthritis, then my hypothesis would be supported.

...when we were asked to name the type of pathway (in the question with the nerves diagram), did everyone put reflex (spinal)?

[annie]

1) FOr the use of copper what did ppl write?
2) The first short answer i think where you had to compare and say why the graphs were the same what did ppl write?
3) the interneuron what letter did ppl write/?
4) how did ppl design their experiment>? just curious??/

1: Use of copper: cofactor in enzymes
2: light is a necessary input for photosynthesis, so availability of light was limiting factor, hence phs rate would correspond to the amount of light absorbed
3: i forget which letter exactly, but its the one in middle between the 2 molecules

4: i think it was a 5 mark question im not sure if i managed to clinch all the marks
Hypothesis (they asked for one):
absence of Vitamin d in mice will have greater incidence in Rheumatoid arthritis.

- 2 genetically identical groups of 50 mice
- exposed to same conditions first group (A) of mice had vitamin d tablets incorporated into its diet
- other group (B) did not get vitamin d
- wait a few weeks and see mice remaining
- less mice in group B than A would support the hypothesis

[annie]

Yeah i got down reflex arc

http://content.answers.com/main/content/img/oxford/Oxford_Sports/0199210896.reflex-arc.1.jpg

Im 100% sure the middle on in the diagram they gave us is the interneuron now 

[bucket]

For that experiment question, i stressed that one group would be deprived of vitamin D whilst the other received safe amounts constantly, the information clearly said that the scientist was suggesting that the disease was caused by a lack of Vitamin D, not that Vitamin D would cure the disease so in order for the hypothesis to be supported, the group that was deprived from Vitamin D would have to have had a much higher incidence of rheumatoid arthritis in it's numbers after a specific period of time.

[JL_91]

For that experiment question, i stressed that one group would be deprived of vitamin D whilst the other received safe amounts constantly, the information clearly said that the scientist was suggesting that the disease was caused by a lack of Vitamin D, not that Vitamin D would cure the disease so in order for the hypothesis to be supported, the group that was deprived from Vitamin D would have to have had a much higher incidence of rheumatoid arthritis in it's numbers after a specific period of time.

My interpretation was different...the background info suggested that the disease was caused by Vitamin D deficiency, yes. But the mice they 'gave' us for use in our experimental design were already naturally suffering from rheumatoid arthritis, so I took that as meaning the mice already had a possible Vitamin D deficiency, i.e. they don't need to be deprived as such, they are already deficient. So I had the experimental group receiving x vitamin D pills a day (to ensure that each mouse got precisely the same amount).

[bucket]

Where did it say that they were already suffering from disease?
I said that none of the mice would have the disease to begin with, and then given that all other factors are controlled, those which are deprived from Vitamin D should develop the disease whilst those who receive regular Vitamin D supplements shouldn't. :S:S
I was surprised that whole question was worth 5 marks, it was only worth 3 in the past O_O.

[username]

What did you guys write for the process of rejection of transplanted tissue?

[JL_91]

Where did it say that they were already suffering from disease?
I said that none of the mice would have the disease to begin with, and then given that all other factors are controlled, those which are deprived from Vitamin D should develop the disease whilst those who receive regular Vitamin D supplements shouldn't. :S:S
I was surprised that whole question was worth 5 marks, it was only worth 3 in the past O_O.

I'm very certain that at the end of the paragraph it said that the mice available had already 'naturally developed rheumatoid arthritis', that's what I based my whole answer on. Anyway - rheumatoid arthritis is an autoimmune disease, which more often than not have a genetic basis, and may be compounded by factors such as the vitamin D deficiency scenario they gave us...so if you were using mice that didn't have the disease to begin with, you wouldn't know for sure if they were ever going to develop the disease in the first place (they might not have been genetically inclined to developing it), if that sort of makes sense lol. It was a lot to do with reducing the progress of rheumatoid arthritis, I believe.

[annie]

Where did it say that they were already suffering from disease?
I said that none of the mice would have the disease to begin with, and then given that all other factors are controlled, those which are deprived from Vitamin D should develop the disease whilst those who receive regular Vitamin D supplements shouldn't. :S:S
I was surprised that whole question was worth 5 marks, it was only worth 3 in the past O_O.

I'm very certain that at the end of the paragraph it said that the mice available had already 'naturally developed rheumatoid arthritis', that's what I based my whole answer on. Anyway - rheumatoid arthritis is an autoimmune disease, which more often than not have a genetic basis, and may be compounded by factors such as the vitamin D deficiency scenario they gave us...so if you were using mice that didn't have the disease to begin with, you wouldn't know for sure if they were ever going to develop the disease in the first place (they might not have been genetically inclined to developing it), if that sort of makes sense lol. It was a lot to do with reducing the progress of rheumatoid arthritis, I believe.

Where did it say that they were already suffering from disease?
I said that none of the mice would have the disease to begin with, and then given that all other factors are controlled, those which are deprived from Vitamin D should develop the disease whilst those who receive regular Vitamin D supplements shouldn't. :S:S
I was surprised that whole question was worth 5 marks, it was only worth 3 in the past O_O.

I'm very certain that at the end of the paragraph it said that the mice available had already 'naturally developed rheumatoid arthritis', that's what I based my whole answer on. Anyway - rheumatoid arthritis is an autoimmune disease, which more often than not have a genetic basis, and may be compounded by factors such as the vitamin D deficiency scenario they gave us...so if you were using mice that didn't have the disease to begin with, you wouldn't know for sure if they were ever going to develop the disease in the first place (they might not have been genetically inclined to developing it), if that sort of makes sense lol. It was a lot to do with reducing the progress of rheumatoid arthritis, I believe.

OH NOOOOOOOOO
5 MARKS
5 MARKS
5 WHOLE MARKS
ON AN EASY APEPR

NOOOOOOOOOOOOOOOOOOOOOOO