VCE Biology Exam Discussion and Solutions

[Roadrunnerani]

Hey Guys; so here's what I wrote:
- Seconary immune response (because Lysozymes are also technically found in the phagocytes)
- MegaFauna may have been docile as they'd never encountered humans before (increasing the liklihood that they'd be hunted)
- Antiseptics could be used to wash skin; disinfectant for hard surfaces (to clean for a hospital)
- Ethical issues: Should we tell the parents if the child carries a heritable disease? What happens if the disease doesn't develop (i.e. phenotype is also formed as part of an interaction with the enviroment)
- I said "Sterile means that the substance has no pathogens in it. In this context, the milk is not sterile."

[ardria]

I was unusually and extremely rushed for time. I was really careful doing MCQ because I could tell it was easy to trip up and pick the answer that "seemed" right if you rushed it. My examiner teacher said this was definitely an "unfair" exam in how mean and vague it suddenly became, especially compared to 2016's relative straight-forwardness.

Do these answers sound valid? They are the ones I'm not entirely confident in.

- MCQ 40: Last option which was that it was transgenic. My thinking was that it's transgenic because RNA is inserted into the plant, and the RNA is genetic material not usually found in the organism.

- The answer for the different proteins from one gene question could only have been alternative splicing of exons, sorry guys . I feel the vast majority of the state wouldn't have known this answer. I only knew cus I did some wider reading.

- I said: "innate, non-specific immunity (2nd line of defense)"

- For the question about antibody function, I answered with descriptions of both agglutination and neutralization of the specific antigen.

- Sterile meaning: 'No pathogenic microbes present, e.g. bacteria'.

- For hospital sterilization methods, I took a totally wild guess and said:
1. Frequent sanitisation/disinfection of surfaces using santising/disinfecting chemicals (hahaha). Then I explained how this prevents spread of germs.
2. Frequent hand-washing of staff, patients and visitors after coming into contact with sick people or contaminated objects.

- I thought the mass extinction of megafauna question was so silly! For the 3 marker bit I had to rush it so I said something like:
"Arrival of First humans and their behavior caused extinction of many megafauna due to behavior like excessive hunting. Their behaviour also resulted in damage to ecology and habitat destruction that caused megafauna to go extinct".
Which I felt was just paraphrasing half the passage? I had no idea how to hit that 3rd mark.

For the 6-marker I believe I did:
- Fire plants(?) not going through genetic bottleneck something something, because this means burning of the plants couldn't have damaged ecology
- Aborigine population not very big, because it's unlikely they would've had an impact great enough to cause mass extinctions
- Can't remember 3rd...I think it was about the megafauna and Aborigines not existing at the same time so Aborigines couldn't have caused their extinction


- For the cockroach experiment controlled variables (omg, this was tough), I put:
1. Same amount of food given to cockroach. Explanation was cus glucose from food is a reactant of cellular respiration so the amount of it affects rate of cellular respiration and thus O2 and CO2 levels.
2. Same level of activity cockroach is allowed to have. Because more activity > more the cockroach respires, affecting O2 and CO2 levels. Eeek, dunno about this one haha.

[neenah]

Q39 was the one about STR and you had to match the up individuals or something, it seemed like more than one option was right in my head so I kinda had difficulty choosing

[chrisjudd00]

What did u say for q39?

[PhoenixxFire]

I think I said that individual 4 was the kid of 1 & 2. I went through them all and that's the only one that worked. (I think it was that one) I thought it was easy

[chrisjudd00]

But that would mean the STR's from the child would have to come from the parents. Thus every number would have to be common with one of the parents and i didnt think they were but i could be wrong.

[JaeSunRyoo]

I think that one was clear, there was one option that had one common allele for the child with one parent only, and as far as I could see, I think PhoenixxFire was right in saying that it was the option with individual 4 being the child of 1/2, or some individual being the child of a couple. I can't remember exactly, but we can discuss it further once the solutions/paper are uploaded.

[chrisjudd00]

Yeah its hard to discuss without having the question in front of us, so we'll wait till they come out.

[ardria]

But that would mean the STR's from the child would have to come from the parents. Thus every number would have to be common with one of the parents and i didnt think they were but i could be wrong.

I chose the Individual 4/Parents 1 +2 answer as well simply because the child's STR markers were more similar to the parents' than the other similar answer.

[Ahmad_A_1999]

I was unusually and extremely rushed for time. I was really careful doing MCQ because I could tell it was easy to trip up and pick the answer that "seemed" right if you rushed it. My examiner teacher said this was definitely an "unfair" exam in how mean and vague it suddenly became, especially compared to 2016's relative straight-forwardness.

Do these answers sound valid? They are the ones I'm not entirely confident in.

- MCQ 40: Last option which was that it was transgenic. My thinking was that it's transgenic because RNA is inserted into the plant, and the RNA is genetic material not usually found in the organism.

- The answer for the different proteins from one gene question could only have been alternative splicing of exons, sorry guys . I feel the vast majority of the state wouldn't have known this answer. I only knew cus I did some wider reading.

- I said: "innate, non-specific immunity (2nd line of defense)"

- For the question about antibody function, I answered with descriptions of both agglutination and neutralization of the specific antigen.

- Sterile meaning: 'No pathogenic microbes present, e.g. bacteria'.

- For hospital sterilization methods, I took a totally wild guess and said:
1. Frequent sanitisation/disinfection of surfaces using santising/disinfecting chemicals (hahaha). Then I explained how this prevents spread of germs.
2. Frequent hand-washing of staff, patients and visitors after coming into contact with sick people or contaminated objects.

- I thought the mass extinction of megafauna question was so silly! For the 3 marker bit I had to rush it so I said something like:
"Arrival of First humans and their behavior caused extinction of many megafauna due to behavior like excessive hunting. Their behaviour also resulted in damage to ecology and habitat destruction that caused megafauna to go extinct".
Which I felt was just paraphrasing half the passage? I had no idea how to hit that 3rd mark.

For the 6-marker I believe I did:
- Fire plants(?) not going through genetic bottleneck something something, because this means burning of the plants couldn't have damaged ecology
- Aborigine population not very big, because it's unlikely they would've had an impact great enough to cause mass extinctions
- Can't remember 3rd...I think it was about the megafauna and Aborigines not existing at the same time so Aborigines couldn't have caused their extinction


- For the cockroach experiment controlled variables (omg, this was tough), I put:
1. Same amount of food given to cockroach. Explanation was cus glucose from food is a reactant of cellular respiration so the amount of it affects rate of cellular respiration and thus O2 and CO2 levels.
2. Same level of activity cockroach is allowed to have. Because more activity > more the cockroach respires, affecting O2 and CO2 levels. Eeek, dunno about this one haha.

Hahahaha this is so relatable, the trial exams I was doing I could finish with an hour left, I don't know what happened today and yeah 2016 was easier for sure

[VH]

For the question where you had to suggest two extra control variables, would giving the cockroach the same amount of water each day, been a valid answer?   

[PhoenixxFire]

Compared to my answers, definitly 😂

[ardria]

Hahahaha this is so relatable, the trial exams I was doing I could finish with an hour left, I don't know what happened today and yeah 2016 was easier for sure

Same for me! I was finishing significantly early in trial exams but finished seconds before time was up today. I think it was largely because only like 5% of the MCQ were ones you could skim-read and know the definite answer, whereas I was used to it being more like 30-40% or something in trial exams.

Also a lot of the short answer questions had long and detailed premises that you had to read fully to make sure you weren't going to make a wrong assumption, e.g. the runner/ramet one where the questions were straightforward and quite simple but you had to read and digest so much text.

I feel like the style of this exam made it more advantageous to know extension stuff and general knowledge of the world (e.g. the sterilization stuff) I feel like this was one of those exams where doing 150 practice exams wouldn't have been significantly more advantageous than doing like 15. Like, you could've done 150 practice exams (not that I did this many) and still struggled. Am I the only one that feels this way?

[rainbowsparkles15]

How did everyone answer the 3 mark question asking how amino acids were joined?

For the cockroach controls:
-Same diet/ amount of food
-Same amount of exercise (though I'm not sure how this could be tested!)

For the same gene but different proteins:
-Alternative exon splicing but not sure how to get 3 marks out of this?

For the STR multiple choice (Q39):
-D, Individual 4's parents are 1&2

Multiple choice 40:
-Think I chose the transgenic option, D, but quite unsure!

6 mark extinction:
-Not very big population so unlikely to cause mass extinction
-Evidence they coexisted (wombat mammal or something)
-Evidence that they had died out tens of thousands of years earlier so First Australians didn't cause extinction

Type of immune system:
Innate
 

[ardria]

How did everyone answer the 3 mark question asking how amino acids were joined?

I word-vomited all this Chemistry 3/4 stuff cus I had no idea what the 3 marks were for.
- Condensation reaction where amine group of amino acid joined with carboxyl group of another amino acid.
- H2O molecule removed
- Resulting bond is peptide bond which is a covalent bond

For the cockroach controls:
-Same diet/ amount of food
-Same amount of exercise (though I'm not sure how this could be tested!)

Woohoo I said exact same thing.

For the same gene but different proteins:
-Alternative exon splicing but not sure how to get 3 marks out of this?

I don't remember it being 3 marks but I explained in detail what the process entailed.