2014 VCE Biology Exam Solutions by Scooby

[Scooby]

Hey everyone!

I've written up some suggested solutions for the short answer section of yesterday's exam if you want to have a look!

If you do, and you find that for certain questions you wrote something really different to what I did, don't be disheartened - there will definitely be things they end up accepting for certain questions that I haven't included

If you disagree with anything I've written, definitely let me know!

Sorry that Q2 and part of Q12 are missing - the pictures I used were blurry and I had trouble reading the questions. Once I can get a hold of some clearer pictures, I'll go back and add in some answers for them too

Regardless of what happens on results day, you should all be proud of the effort you've put into what is a really tough subject over this year. Congratulations on finishing Bio!

UPDATE:

12b
i)
•   Variation existed in a population of M. africanavus
•   Natural selection acted  on this population over millions of years (or a description of this process)
•   If members of this population would no longer be able to mate (producing fertile offspring) with members of the initial M.africanavus population, it is considered as consisting of a different species (ie. M. primigenius)

ii)
•   Major environmental changes occurred
•   M. primigenius was unable to adapt to these changes and extinction occurred
•   E. maximus was able to adapt this change, possibly because of a greater genetic diversity than M. primigenius

[dankfrank420]

Hey Scooby, for question 9A do you still think I can get marks if I wrote polypeptide instead of protein?

Also for 11C, would the use of tools by freeing up hands and more efficient travel --> more migration be acceptable?

Finally, would mutations be another source of variation in males for question 6b?

Edit: Forgot to say, thanks for the (mock) solutions!

[vcestudent123]

Loved the answer for Q 11 bii :p

[SwagG]

Thanks Scooby! Yeah basically same questions as dan frank. What do you think?

[Scooby]

Hey Scooby, for question 9A do you still think I can get marks if I wrote polypeptide instead of protein?

Also for 11C, would the use of tools by freeing up hands and more efficient travel --> more migration be acceptable?

Finally, would mutations be another source of variation in males for question 6b?

Edit: Forgot to say, thanks for the (mock) solutions!

Yeah, for 11C, your answer is better than mine ahah, I had trouble thinking of something decent but yeah, they'll accept that

Yup, the question asked for how it "can" occur, so I'd say they'll accept mutation as another source of variation

Loved the answer for Q 11 bii :p

ahah thanks, that question was definitely an interesting one

Thanks Scooby! Yeah basically same questions as dan frank. What do you think?

It was a fair exam, but there were definitely some challenging question in there. The A+ cut off should drop a fair bit compared with last year - there was definitely a step up in difficulty this year!

[dankfrank420]

Yeah, for 11C, your answer is better than mine ahah, I had trouble thinking of something decent but yeah, they'll accept that

Yup, the question asked for how it "can" occur, so I'd say they'll accept mutation as another source of variation

Cheers, but could you please answer my first question? Really panicking that I threw a mark away... 

[Scooby]

Hey Scooby, for question 9A do you still think I can get marks if I wrote polypeptide instead of protein?

Woops, forgot to answer this part - yeah, you should still get a mark for that

[Scooby]

Legend.

But... I've got a few queries if someone won't mind answering them:
4c. I drew 3 antibodies attached each to one antigen on the same pathogen and another antibody moving towards an antigen of different pathogen (drew an arrow from the binding site to the antigen saying the antibody moves to bind there etc.) Is that sufficient?

4cii. Wrote macrophages instead of phagocytes... Still right?

5c. Just wrote passive cause the mother doesn't produce antibodies herself but not sure if this is in depth enough.

9b. Said one chromosome number doesn't have a homologous pair when compared rather than it only has 45 chromosomes. This is still acceptable yeah?

11c. Is 'Choose a protein common to all species under analysis.' absolutely essential?

Sorry for the long post. Thanks

4 ci. Yeah, that's definitely fine

4 cii. Yup, macrophages will definitely be accepted too

5c. That should be alright. I think how it'll go is that they'll give one mark for identifying that it's passive immunity, and then the second mark for saying that she doesn't manufacture her own antibodies/memory cells OR that protection ceases after the treatment is discontinued

9b. Yup, should be fine

11c. Choosing a protein common to all the species analysed is an important part of the procedure, of course (you don't want to extract different proteins from each of the species, or there'll be no point), but I'll be surprised if you're penalised just because you didn't state that explicitly

[Scooby]

I've got a clearer copy of the exam now, so I'll have solutions for the questions I missed posted soon!

[heymanhru]

For question 10.A would I be wrong if I mentioned the sex of the bee in the phenotype?

I put 25% for Red Male, 25% Black male...etc.

[dankfrank420]

@Heymanhru

Yeah you'll be ok with that

Hey Scooby,

Do you think they'll accept a description of allopatric speciation for 12bi? Ie:

- populations of M. africanavus become isolated from eachother preventing  gene flow
- these populations faced different selection pressures, hence developing different phenotypes to suit these pressures
- eventually these populations were so different that they could no longer interbreed and produce fertile offspring when brought back togther
- hence a new species was formed (M. primigenius)

Also for 12bii, do you think they'd accept this

- M primigenius faced extreme selection pressures (such as climate change and human hunting) that the E maximus was not subjected to
- E maximus is more suited to its environment

[katiesaliba]

For question 10.A would I be wrong if I mentioned the sex of the bee in the phenotype?

I put 25% for Red Male, 25% Black male...etc.

You're supposed to mention the sex as it's a part of an organism's phenotype

Do you think they'll accept a description of allopatric speciation for 12bi? Ie:

- populations of M. africanavus become isolated from eachother preventing  gene flow
- these populations faced different selection pressures, hence developing different phenotypes to suit these pressures
- eventually these populations were so different that they could no longer interbreed and produce fertile offspring when brought back togther
- hence a new species was formed (M. primigenius)

It's not speciation though because the entire species evolves, thus undergoing evolution via natural selection. The two populations wouldn't be able to interbreed technically because only one exists. Theoretically if they were brought back together somehow, yes they would not produce viable offspring, but that's impossible... 

[dankfrank420]

It's not speciation though because the entire species evolves, thus undergoing evolution via natural selection. The two populations wouldn't be able to interbreed technically because only one exists. Theoretically if they were brought back together somehow, yes they would not produce viable offspring, but that's impossible... 

So thats 0/3 then? 

[katiesaliba]

So thats 0/3 then? 

No! I think you'd definitely still get marks for mentioning different selection pressures. That question was so ambiguous though :\

[dankfrank420]

No! I think you'd definitely still get marks for mentioning different selection pressures. That question was so ambiguous though :\

Yeah, hopefully they recognise that and accept a wider range of responses.