Suggested Answers to 2013 VCAA Units 3/4 Biology Exam

[Panicmode]

Here are my suggested answers .

Any comments/queries/corrections/errors/questions, feel free to post here or give me a PM.


EDIT:

Here is a copy of the exam supplied by Alwin.

[Stick]

Thanks. Looks like I'll probably be losing a mark here and there for bad wording.

One query about 10c. Could one also say the origin of the virus was the horseshoe bats, given that strains 5, 6 and 7 would eventually have come from an ancestor that appeared to infect horseshoe bats? I guess in hindsight it wasn't very clear, because the question didn't really indicate what it meant by 'origin', in that one could have made the link to either the most recent common ancestor, or drew upon the phylogeny as a whole (as I did).

[ctoom14]

For question 1c)
I gave light and water as inputs and said that

-water provides H+ ions to form with CO2 to form glucose
-light provides energy in form of tap for cyclic set of reactions to form glucose

Do you thinks that would be accepted and if not, why?

[swagsxcboi]

For question 1c)
I gave light and water as inputs and said that

-water provides H+ ions to form with CO2 to form glucose
-light provides energy in form of tap for cyclic set of reactions to form glucose

Do you thinks that would be accepted and if not, why?

No, the question asked for the stage of photosynthesis that uses carbon dioxide, which is the light independent stage
Water and light are inputs of the light dependant stage

[swagsxcboi]

Thanks. Looks like I'll probably be losing a mark here and there for bad wording.

One query about 10c. Could one also say the origin of the virus was the horseshoe bats, given that strains 5, 6 and 7 would eventually have come from an ancestor that appeared to infect horseshoe bats? I guess in hindsight it wasn't very clear, because the question didn't really indicate what it meant by 'origin', in that one could have made the link to either the most recent common ancestor, or drew upon the phylogeny as a whole (as I did).

I said that it originated from the horse shoe bats too 

[mich_wen]

Hey, how do we actually view your answers? No link has come up on my computer for the suggested answers, just a link to the exam 

[Panicmode]

Hey, how do we actually view your answers? No link has come up on my computer for the suggested answers, just a link to the exam 

They are linked at the bottom beneath my post; just click on either the pdf or docx version below to download.

Thanks. Looks like I'll probably be losing a mark here and there for bad wording.

One query about 10c. Could one also say the origin of the virus was the horseshoe bats, given that strains 5, 6 and 7 would eventually have come from an ancestor that appeared to infect horseshoe bats? I guess in hindsight it wasn't very clear, because the question didn't really indicate what it meant by 'origin', in that one could have made the link to either the most recent common ancestor, or drew upon the phylogeny as a whole (as I did).

Hmm, I suppose it could be interpreted like that. As long as you made sure that you were referring to the phylogeny as a whole, (maybe saying something like the original SARS seems to have begun in horseshoe bats) then you might get the marks. Because it mentioned the word strain I interpreted it as asking for the immediate origin rather than the origin of the SARS virus in general.

However, I'm not an examiner, and I don't know what they'll accept. There's every chance that they want your answer and not the one I've suggested.

For question 1c)
I gave light and water as inputs and said that

-water provides H+ ions to form with CO2 to form glucose
-light provides energy in form of tap for cyclic set of reactions to form glucose

Do you thinks that would be accepted and if not, why?

The question specifically asked for inputs of the light independent stage of photosynthesis . Water and light are both inputs of the light dependent stage.

[mich_wen]

Just wondering, for the selective advantage associated with the use of sewing needles, could you instead speak about how the use of sewing needles implies the capability of a precision grip, thereby giving them a greater ability to use/ make tools?

[psyxwar]

Just wondering, for the selective advantage associated with the use of sewing needles, could you instead speak about how the use of sewing needles implies the capability of a precision grip, thereby giving them a greater ability to use/ make tools?

I'd say no, because that's not actually a selective advantage of the needle.

[lucylovestennis]

I said that they were a common ancestor of horseshoe bats and diverged from them....
also, would it have been ok to say that ATP and NADPH were used as inputs to help make glucose?

[swagsxcboi]

I said that they were a common ancestor of horseshoe bats and diverged from them....
also, would it have been ok to say that ATP and NADPH were used as inputs to help make glucose?

Check the solutions he posted.
ATP and NADPH are fine

[simpak]

Based on the information given the acceptable answer should be palm civet.
Based on actual knowledge of SARS, bats are the original source of SARS.  Civets are an intermediate host in which amplification occurs.

[swagsxcboi]

Based on the information given the acceptable answer should be palm civet.
Based on actual knowledge of SARS, bats are the original source of SARS.  Civets are an intermediate host in which amplification occurs.

can you explain why it's palm civets?
It says that species 5 and 6 are in humans and species 7 is palm civets
and all other species are found in bats. Doesn't that mean that the virus evolved from a virus that was found in bats?

[RealestNigerian]

can you explain why it's palm civets?
It says that species 5 and 6 are in humans and species 7 is palm civets
and all other species are found in bats. Doesn't that mean that the virus evolved from a virus that was found in bats?

it's talking about the strain

[Stick]

That has to be as ambiguous as hell... Oh well, it's a 1 mark question. Harmless stuff.