VCE Biology Question Thread

[AhNeon]

4) Are all the inputs and outputs I have correct?

Isn't water an output for the ETC?

[blacksanta62]

Hey guys, just finishing off my research SAC for biology and I'm having some trouble interpreting a question:
"How do cultural, technological and biological evolution work in relation to GM foods?"
I have no idea what to talk about.
Also, if asked how humans have changes evolutionary processes, would talking about selective breeding and contrasting it to natural selection suffice?

Thanks

Bump
Anyone have any suggestions and a confirmation on the last part of the  question?
Thanks

[instax101]

Hey again,

With this question from VCAA 2012 Exam 1, why is the answer C? Edrolo goes through the same question and Douch puts A, like I did. My understanding is that MHC 1 molecules present foreign antigens to Tc cells only.

Thanks

[vox nihili]

Hey again,

With this question from VCAA 2012 Exam 1, why is the answer C? Edrolo goes through the same question and Douch puts A, like I did. My understanding is that MHC 1 molecules present foreign antigens to Tc cells only.

Thanks


(Image removed from quote.)

Bit of a shitty question. A is definitely not correct though. In your explanation, you've correctly identified what MHC class I molecules are for, so I won't go into that.

B-cells can really bind to antigen in any context, including if it's presented on an MHC class I molecule. This would be kind of odd, and it's really just splitting hairs, but yeah, that's why C is the answer.

Isn't water an output for the ETC?

True

[AhNeon]

What is the answer of question 2a short answer exam 2, 2008.
I'm not sure, but what i got from the examination report is that the mother's claim is supported?

[vox nihili]

What is the answer of question 2a short answer exam 2, 2008.
I'm not sure, but what i got from the examination report is that the mother's claim is supported?

So the parents are:

FGA 20,20 and 20, 21 respectively
DS  11,15 and 14, 16 respectively

The newborn baby is:

FGA 20, 20 and DS 11,15

Now all you've got to do is track the alleles. So let's start with FGA

The baby is FGA 20, 20. The mother has a copy of FGA 20 and the father has a copy of FGA 20. So that works

The baby is DS 11, 15. The mother has a copy of both DS 11 and DS 15, so either of those could come from her; however, the father has neither DS 11 or DS 15. Remember that one allele has to come from the mother and the other from the father. The father can't give DS 11 or DS 15; therefore, the baby can't have come from that father.

So all the evidence does indeed support the mother's claim that that ain't her baby

[Butterflygirl]

Cell-mediated response damages the beta cells, leading to type 1 diabetes.
Why would a vaccine containing free floating insulin antigens reduce immune response that leads to type 1 diabetes?

Something about antigens that are free floating are more difficult to detect or something?

Another thing:
A series of crosses were conducted and the results were used to determine which colours are dominant or recessive and whether they are autosomal or sex-linked.
In one cross, a red eyed female was crossed with a white eyed male and all offspring expressed red eyed.
Based on the outcome of the cross, explain which eye colour is dominant.

I know its red but how do I explain that with the cross?

Help would be highly appreciated

[Gogo14]

Cell-mediated response damages the beta cells, leading to type 1 diabetes.
Why would a vaccine containing free floating insulin antigens reduce immune response that leads to type 1 diabetes?

Something about antigens that are free floating are more difficult to detect or something?

Another thing:
A series of crosses were conducted and the results were used to determine which colours are dominant or recessive and whether they are autosomal or sex-linked.
In one cross, a red eyed female was crossed with a white eyed male and all offspring expressed red eyed.
Based on the outcome of the cross, explain which eye colour is dominant.

I know its red but how do I explain that with the cross?

Help would be highly appreciated

1.
Unless i'm missing something, it wouldn't. You don't use vaccines for autoimmune diseases
2.
Cross a homozygous red eye with a homozygous white eye.

[Gogo14]

http://m.imgur.com/teNFgUG,BHmepXF
So I came across this question. I got really surprised that vcaa asked something like that,soooo are they likely/ is it possible they will throw a question like that?

[vox nihili]

http://m.imgur.com/teNFgUG,BHmepXF
So I came across this question. I got really surprised that vcaa asked something like that,soooo are they likely/ is it possible they will throw a question like that?

Completely reasonable question. No doubt it's a hard one though. The details of coeliac disease are fairly unimportant in that, though.

Cell-mediated response damages the beta cells, leading to type 1 diabetes.
Why would a vaccine containing free floating insulin antigens reduce immune response that leads to type 1 diabetes?

Something about antigens that are free floating are more difficult to detect or something?

You'd never get asked something like that. Pretty sure it can work but god only knows how.

[Gogo14]

http://m.imgur.com/teNFgUG,BHmepXF
So I came across this question. I got really surprised that vcaa asked something like that,soooo are they likely/ is it possible they will throw a question like that?

Sorry, I meant part D in the second pic

[vox nihili]

Sorry, I meant part D in the second pic

Ohhhh THAT question.

Completely reasonable, otherwise they wouldn't have asked it. Also gimme marks because it's just commonsense.

It's fair to say that that's probably a question that warrants a degree of scrutiny though; it's not their best work.

[Butterflygirl]

1.
Unless i'm missing something, it wouldn't. You don't use vaccines for autoimmune diseases
2.
Cross a homozygous red eye with a homozygous white eye.

For 2 I mean, how do I explain that red is dominant using the results from the cross they performed because I know its not correct to say "There was more red offspring than white".

[AhNeon]

For 2 I mean, how do I explain that red is dominant using the results from the cross they performed because I know its not correct to say "There was more red offspring than white".

Well in that cross all offspring will have red eyes as it is the dominant allele and all resulting offspring from the cross will be heterozygous

Also, is this answer acceptable for the question 'explain how isolation may result in speciation'.
-Groups of species are isolated and thus, there is no gene flow between them
-Populations face different selective pressures
-Different phenotypes are selected for and thus, are likelier to be passed down to the next generation
-Over time the differences accumulated until members of the 2 groups are unable to produce fertile offspring when mated together

[Gogo14]

Well in that cross all offspring will have red eyes as it is the dominant allele and all resulting offspring from the cross will be heterozygous

Also, is this answer acceptable for the question 'explain how isolation may result in speciation'.
-Groups of species are isolated and thus, there is no gene flow between them
-Populations face different selective pressures
-Different phenotypes are selected for and thus, are likelier to be passed down to the next generation
-Over time the differences accumulated until members of the 2 groups are unable to produce fertile offspring when mated together

Yep, great. Each bullseye hit.

What the threshold voltage in an action potential indicate?
I can't seem to improve my scores for each practice exam I do. They are all really similar. Any tips?