Suggested Answers to 2013 VCAA Units 3/4 Biology Exam

[swagsxcboi]

it's talking about the strain

which strain the human strain evolved from? what? 

[Panicmode]

which strain the human strain evolved from? what? 

The question asked for the origin of the strain that affected humans, not the origin of the SARS virus.

The SARS virus may have started in horeshoe bats, but the phylogenetic tree indicated that the human strain was likely derived from one affecting palm civets.
That was the conclusion I drew, but I can clearly see how others would view it differently. Again, these are just my suggested solutions.

[Diverse]

Can someone explain the answer for q24 MC?

I chose B, A and B thinking that its AO x BO; I'm guessing I forgot about the Y chromosome?

Cheers.

[Scooby]

Can someone explain the answer for q24 MC?

I chose B, A and B thinking that its AO x BO; I'm guessing I forgot about the Y chromosome?

Cheers.

You mean 24 or 25?

[Stick]

Can someone explain the answer for q24 MC?

I chose B, A and B thinking that its AO x BO; I'm guessing I forgot about the Y chromosome?

Cheers.

I think you looked at the wrong answer (Q24) for Question 25, because you're right.

[Diverse]

I think you looked at the wrong answer (Q24) for Question 25, because you're right.

Thank the lord!

I'm really happy how I pulled up!

[simpak]

Sorry I've been studying for my [coincidentally] Virology exam and look [coincidentally] at what lecture I am up to... http://imgur.com/NqLnIR5

Anyway, on second review of the paper I'm kind of changing my mind to agree with bats being the answer.  Maybe it's just because I've been studying them for the last hour though!  Anyway I think because it says 'origin' and strain 8 and strain 4 both infect bats you can definitely say bats are the 'origin' but you can't definitely say civet is the origin, because although it MAY be the origin based on the graph, you see divergence into three at the same time.  So I am changing my answer to BAT based on 'what conclusion can be drawn' phrasing.

[swagsxcboi]

Sorry I've been studying for my [coincidentally] Virology exam and look [coincidentally] at what lecture I am up to... http://imgur.com/NqLnIR5

Anyway, on second review of the paper I'm kind of changing my mind to agree with bats being the answer.  Maybe it's just because I've been studying them for the last hour though!  Anyway I think because it says 'origin' and strain 8 and strain 4 both infect bats you can definitely say bats are the 'origin' but you can't definitely say civet is the origin, because although it MAY be the origin based on the graph, you see divergence into three at the same time.  So I am changing my answer to BAT based on 'what conclusion can be drawn' phrasing.

  some hope 

[lucylovestennis]

also....whilst i initially thought adrenalin was a lipid soluble hormone....the question said that its receptor was on the exterior surface of the plasma membrane...hence the nature of its structure has to be a protein?

[simpak]

  some hope 

Yup I am the be-all-end-all of VCE Biology.  As Panicmode has said, it's just his opinion as it is mine (which I have now CONVENIENTLY altered too, something you guys don't get to do).  Even 50s make mistakes!  I definitely lost a few marks on my Biology exams in VCE.
I reckon they may accept both answers anyway and it's only one mark down so I'm sure you'll all be okay!

lucylovestennis; not necessarily, it just needs to be a polar molecule.  Adrenaline is a catecholamine which is a kind of organic molecule but it doesn't have peptide bonds so we can't classify it as a protein.  Additionally, it would need a minimal amount of amino acids to be classified as a protein rather than a peptide.  It's not a peptide, but since most hormones are small, we can assume that if it contained amino acids it still wouldn't be classified as a 'protein' because it wouldn't contain enough.

[Panicmode]

also....whilst i initially thought adrenalin was a lipid soluble hormone....the question said that its receptor was on the exterior surface of the plasma membrane...hence the nature of its structure has to be a protein?

Not necessarily. For instance, water isn't lipid soluble but it's not a protein.

In the case of adrenalin, it's actually an amino acid derived hormone, so it's not a protein.

[swagsxcboi]

Not necessarily. For instance, water isn't lipid soluble but it's not a protein.

In the case of adrenalin, it's actually an amino acid derived hormone, so it's not a protein.

so you don't think they'll accept "water soluble (peptide based)" as an answer?
How pedantic have vcaa been in the past?

[misslulu96]

PLEASE HELP ME 
Well I worked out approximately what I would have got.. I can't remember all my answers but looks like I got 45% for it all :c

I was not expecting to get a good score because I have had some personal issues during these weeks but my aim was to pass at least..

What kind of study score will I get since my SAC marks have been relatively good (80-95%)? Just an estimate

I am also getting special consideration or a derived score whatever it is! (when they look at your SAC marks and what your teacher thought you would have got) so I dont know if that will change things but just ignore that and guess what I would get raw.

[Damoz.G]

PLEASE HELP ME 
Well I worked out approximately what I would have got.. I can't remember all my answers but looks like I got 45% for it all :c

I was not expecting to get a good score because I have had some personal issues during these weeks but my aim was to pass at least..

What kind of study score will I get since my SAC marks have been relatively good (80-95%)? Just an estimate

I am also getting special consideration or a derived score whatever it is! (when they look at your SAC marks and what your teacher thought you would have got) so I dont know if that will change things but just ignore that and guess what I would get raw.

Sorry to hear about that.

Ummm....do you know what your Rank is for everyone doing Bio in your cohort?

[misslulu96]

Sorry to hear about your situation.

Ummm....do you know what your Rank is in your cohort doing Bio?

No my school does not tell that but there are some really smart students in my class so I would say at the lower end