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Author Topic: 2020 VCAA Biology Exam Solutions  (Read 13905 times)

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darkz

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2020 VCAA Biology Exam Solutions
« on: November 17, 2020, 10:21:16 am »
Please note:
- The exam is over, so use this wisely. It will not change your score.
- These answers were written with medium-low care and therefore there are likely to be errors (also forgotten half the content lol). If you see any errors, please let me know and I'll fix them up. * denotes questions that I find debatable.

Multiple Choice
Spoiler
1.   B
2.   C
3.   B
4.   C
5.   D
6.   B
7.   D
8.   C
9.   B
10.   A
11.   B*
12.   C
13.   D
14.   B
15.   D
16.   B
17.   B
18.   A
19.   B
20.   A
21.   C
22.   A
23.   A
24.   B
25.   D
26.   D
27.   C
28.   C
29.   C
30.   C
31.   D
32.   D
33.   D
34.   C
35.   B
36.   D
37.   B
38.   C
39.   A
40.   A

Short Answer - these are rough answers, extra detail may be required/not all acceptable responses included.

Question 1
Spoiler
a.
         GA = protein packaging into vesicles for secretion
         M = site of aerobic cellular respiration
b.   
         i.   Exocytosis
         ii.   Exocytosis is the energy-dependent mode of transport involving the fusion of secretory vesicles with the plasma membrane before releasing the product into the extracellular environment. Secretory granules are a subset of secretory vesicles, containing the products to be secreted.
Question 2
Spoiler
a.
         From left to right – phosphate, ribose sugar, nitrogenous base (sugar should be specific, e.g. pentose sugar/deoxyribose probz not accepted)
b.
         tRNA = facilitates the transport of complementary amino acid to the ribosome during transcription
         mRNA = carries the genetic code in the form of RNA for protein production
c.
         Addition of a poly A or guanine cap = assist in stability/survivability of the mRNA
         Splicing = remove introns and merge exons together, facilitate in production of different proteins from the same sequence of DNA
Question 3
Spoiler
a.
         Enzymes have an optimum temperature at which they operate. Low temperatures = reduce activity, high temperature = denature.
b.
         Green light normally reflected and therefore not absorbed. Red light can be absorbed better and therefore can increase the rate of the light dependent stage = increase crop yield.
c.
         Apply theory of endosymbiosis. E.g. have their own ribosomes, double membrane.

Question 4
Spoiler
a.
         i. X = receptor protein , Y = nuclear membrane
         ii. Exocytosis
b.
         1 = reception, binding of signalling molecule with receptor
         2 = signal transduction, production of secondary messengers which amplify the signal
         3 = response, altered (increased) gene expression
c.
         hydrophilic, cannot pass through the plasma membrane and therefore uses an extracellular receptor
Question 5
Spoiler
a.
         Cytotoxic T cells detect changes in MHC 1 expression (i.e. no longer self), using perforin/granzymes to initiate apoptosis or cell death of virally infected cells
b.
         i. lymphatic system filters fluid that leaks out of the systemic circulation, which is subsequently checked by immune cells which are located in lymph nodes i.e. facilitates the detection of pathogens
         ii. T helper, naïve B cell, binding and production of cytokines in response to complementary binding, clonal selection and expansion, activated B cell, plasma B cell and memory B cells, plasma B cells produce antibodies.
Question 6
Spoiler
a.
         cheaper cost, reduced risk of adverse immune reaction
b.
         allergies to the bacteria, many other examples of ethical considerations
Question 7
Spoiler
a.
         substitution point mutation, or missense mutation
b.
         i. Standard natural selection question. Those with lactase could use more food sources = selective advantage, increased passing down of favourable allele to children as increased genetic fitness/survivability, increase in frequency of allele
         ii. Founder effect, broke off from the original population and didn’t have the allele in the gene pool. Bottleneck effect by the same reason. Can’t think of any reasons why it would be selected against? I suppose people had a cow which produced toxic milk and then all those with the gene died? Lol
c.
         Over many generations = selective breeding, breeding those with similar traits together to increase allele frequency.
Question 8
Spoiler
a.
         Amatitlania aiquia and Hypsophyrys nematopus, least amount of time since divergence.
b.
         Burial site undisturbed/rapid burying = sediment in ocean rapidly buries and no other land animals trampling over the remains. High pressure = weight of water above
c.
         carbon dating can be used, measuring ratio if C12 to C14, as the fish is an organic organism. I’d also argue that relative dating or stratigraphy could also be used. Potassium/argon not relevant here.
Question 9
Spoiler
a.
         Features to talk about include position of less centralised foramen magnum, increased brow ridges, not flat face.
b.
         Figure 1 homo egaster and sapiens are depicted to be more closely related together than in figure 2. Also in figure 2, egaster is an ancestor of sapiens instead of the divergent evolution.
c.
         Anywhere reasonable, probably just draw another diverging branch off the sapiens and neanderthalensis branch. Justify with the presence of interbreeding/ shared physical characteristics.
d.
         contradictory evidence, new evidence, inter-breeding, accuracy of dating techniques
Question 10
Spoiler
a.
         Epidemic = localised to Samoa, pandemic = person arrived on plane, so assume that somewhere else is also infected
b.
         babies less than 6 months, protective antibodies from mother via placenta i.e. passive natural immunity
c.
         i. Samoa = 31%, Australia = 95% i.e. 64% difference
         ii. Active induced immunity
         iii. Apply theory of herd immunity i.e. large population vaccinated = protect those who are not since less susceptible hosts to facilitate transmission
d.
         hAnD hYgEiNe, quarantine and screening of overseas travellers
Question 11
Spoiler
a.
         I cbs analysing the results :c , but you’d have to describe the bp for each of the different ones since they’ve provided a ladder and also considering the mark allocation. Also slightly explain the results i.e. why longer migrate less.
b.
         Test tube 1 missing and half of test tube 2 missing, possible reason is that the guy just injected some buffer into test tube 1 lol or didn’t set it up properly.
c.
         Factors include length (as longer = slower), also charge of current (increased = greater attraction, more movement)
d.
         wear gloves, have hAnD hYgEiNe,


« Last Edit: November 17, 2020, 11:39:51 am by darkz »
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darkz

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Re: 2020 VCAA Biology Exam Solutions
« Reply #1 on: November 17, 2020, 11:37:01 am »
All answers uploaded! Let me know if any are wrong :)
2018: Biology [50 + Prems]
2019: English [46], Latin [45], Chemistry [41], Mathematical Methods [48], Specialist Mathematics [41]
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2020: BMedSci, M.D. @ Monash Uni

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bamboozled

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Re: 2020 VCAA Biology Exam Solutions
« Reply #2 on: November 17, 2020, 03:13:02 pm »
Thanks so much. Would you mind posting the actual multiple choice questions though, if you have them?

PhoenixxFire

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Re: 2020 VCAA Biology Exam Solutions
« Reply #3 on: November 17, 2020, 03:30:06 pm »
Thanks so much. Would you mind posting the actual multiple choice questions though, if you have them?
Hey,
Unfortunately VCAA exams are copyrighted so they can't be shared on the forums until they're released by VCAA.
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PhoenixxFire

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Re: 2020 VCAA Biology Exam Solutions
« Reply #4 on: November 17, 2020, 09:21:29 pm »
where could we obtain a copy without VCAA finding out...

Me telling you that would defeat the point of not allowing them to be posted on the forums.
2019: B. Environment and Sustainability/B. Science @ ANU
2020: Just Vibing
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homeworkisapotato

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Re: 2020 VCAA Biology Exam Solutions
« Reply #5 on: November 17, 2020, 10:16:53 pm »
Thank you so much darkz! Appreciate this sososo much! <3
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fwift52

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Re: 2020 VCAA Biology Exam Solutions
« Reply #6 on: November 18, 2020, 09:17:04 am »
Pretty sure 11 was B so you are good there.

homeworkisapotato

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Re: 2020 VCAA Biology Exam Solutions
« Reply #7 on: November 18, 2020, 09:52:21 am »
For 4ai will they accept nucleus as well for Y?
And for 3a, I don't think I specified that lower temperature decreases enzyme activity..I think I just put that optimal temperature has the greatest enzyme-subtrate collisions.. is that fine or did I have to specify lower temperature?
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failingenglish

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Re: 2020 VCAA Biology Exam Solutions
« Reply #8 on: November 18, 2020, 11:31:23 am »
Pretty sure 11 was B so you are good there.
What was 11?

Flybird123

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Re: 2020 VCAA Biology Exam Solutions
« Reply #9 on: November 18, 2020, 03:20:58 pm »
Please note:
- The exam is over, so use this wisely. It will not change your score.
- These answers were written with medium-low care and therefore there are likely to be errors (also forgotten half the content lol). If you see any errors, please let me know and I'll fix them up. * denotes questions that I find debatable.

Multiple Choice
Spoiler
1.   B
2.   C
3.   B
4.   C
5.   D
6.   B
7.   D
8.   C
9.   B
10.   A
11.   B*
12.   C
13.   D
14.   B
15.   D
16.   B
17.   B
18.   A
19.   B
20.   A
21.   C
22.   A
23.   A
24.   B
25.   D
26.   D
27.   C
28.   C
29.   C
30.   C
31.   D
32.   D
33.   D
34.   C
35.   B
36.   D
37.   B
38.   C
39.   A
40.   A

Short Answer - these are rough answers, extra detail may be required/not all acceptable responses included.

Question 1
Spoiler
a.
         GA = protein packaging into vesicles for secretion
         M = site of aerobic cellular respiration
b.   
         i.   Exocytosis
         ii.   Exocytosis is the energy-dependent mode of transport involving the fusion of secretory vesicles with the plasma membrane before releasing the product into the extracellular environment. Secretory granules are a subset of secretory vesicles, containing the products to be secreted.
Question 2
Spoiler
a.
         From left to right – phosphate, ribose sugar, nitrogenous base (sugar should be specific, e.g. pentose sugar/deoxyribose probz not accepted)
b.
         tRNA = facilitates the transport of complementary amino acid to the ribosome during transcription
         mRNA = carries the genetic code in the form of RNA for protein production
c.
         Addition of a poly A or guanine cap = assist in stability/survivability of the mRNA
         Splicing = remove introns and merge exons together, facilitate in production of different proteins from the same sequence of DNA
Question 3
Spoiler
a.
         Enzymes have an optimum temperature at which they operate. Low temperatures = reduce activity, high temperature = denature.
b.
         Green light normally reflected and therefore not absorbed. Red light can be absorbed better and therefore can increase the rate of the light dependent stage = increase crop yield.
c.
         Apply theory of endosymbiosis. E.g. have their own ribosomes, double membrane.

Question 4
Spoiler
a.
         i. X = receptor protein , Y = nuclear membrane
         ii. Exocytosis
b.
         1 = reception, binding of signalling molecule with receptor
         2 = signal transduction, production of secondary messengers which amplify the signal
         3 = response, altered (increased) gene expression
c.
         hydrophilic, cannot pass through the plasma membrane and therefore uses an extracellular receptor
Question 5
Spoiler
a.
         Cytotoxic T cells detect changes in MHC 1 expression (i.e. no longer self), using perforin/granzymes to initiate apoptosis or cell death of virally infected cells
b.
         i. lymphatic system filters fluid that leaks out of the systemic circulation, which is subsequently checked by immune cells which are located in lymph nodes i.e. facilitates the detection of pathogens
         ii. T helper, naïve B cell, binding and production of cytokines in response to complementary binding, clonal selection and expansion, activated B cell, plasma B cell and memory B cells, plasma B cells produce antibodies.
Question 6
Spoiler
a.
         cheaper cost, reduced risk of adverse immune reaction
b.
         allergies to the bacteria, many other examples of ethical considerations
Question 7
Spoiler
a.
         substitution point mutation, or missense mutation
b.
         i. Standard natural selection question. Those with lactase could use more food sources = selective advantage, increased passing down of favourable allele to children as increased genetic fitness/survivability, increase in frequency of allele
         ii. Founder effect, broke off from the original population and didn’t have the allele in the gene pool. Bottleneck effect by the same reason. Can’t think of any reasons why it would be selected against? I suppose people had a cow which produced toxic milk and then all those with the gene died? Lol
c.
         Over many generations = selective breeding, breeding those with similar traits together to increase allele frequency.
Question 8
Spoiler
a.
         Amatitlania aiquia and Hypsophyrys nematopus, least amount of time since divergence.
b.
         Burial site undisturbed/rapid burying = sediment in ocean rapidly buries and no other land animals trampling over the remains. High pressure = weight of water above
c.
         carbon dating can be used, measuring ratio if C12 to C14, as the fish is an organic organism. I’d also argue that relative dating or stratigraphy could also be used. Potassium/argon not relevant here.
Question 9
Spoiler
a.
         Features to talk about include position of less centralised foramen magnum, increased brow ridges, not flat face.
b.
         Figure 1 homo egaster and sapiens are depicted to be more closely related together than in figure 2. Also in figure 2, egaster is an ancestor of sapiens instead of the divergent evolution.
c.
         Anywhere reasonable, probably just draw another diverging branch off the sapiens and neanderthalensis branch. Justify with the presence of interbreeding/ shared physical characteristics.
d.
         contradictory evidence, new evidence, inter-breeding, accuracy of dating techniques
Question 10
Spoiler
a.
         Epidemic = localised to Samoa, pandemic = person arrived on plane, so assume that somewhere else is also infected
b.
         babies less than 6 months, protective antibodies from mother via placenta i.e. passive natural immunity
c.
         i. Samoa = 31%, Australia = 95% i.e. 64% difference
         ii. Active induced immunity
         iii. Apply theory of herd immunity i.e. large population vaccinated = protect those who are not since less susceptible hosts to facilitate transmission
d.
         hAnD hYgEiNe, quarantine and screening of overseas travellers
Question 11
Spoiler
a.
         I cbs analysing the results :c , but you’d have to describe the bp for each of the different ones since they’ve provided a ladder and also considering the mark allocation. Also slightly explain the results i.e. why longer migrate less.
b.
         Test tube 1 missing and half of test tube 2 missing, possible reason is that the guy just injected some buffer into test tube 1 lol or didn’t set it up properly.
c.
         Factors include length (as longer = slower), also charge of current (increased = greater attraction, more movement)
d.
         wear gloves, have hAnD hYgEiNe,
thanks so much man :D so you believe they accept both epidemic and pandemic as long as you give plausible explanation?

ezdebebe

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Re: 2020 VCAA Biology Exam Solutions
« Reply #10 on: November 18, 2020, 04:00:56 pm »
Hey, I'm pretty sure for question 7b u had to be more specific and explain as to why the allele frequency increased more quickly than other mutations or something like that.
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darkz

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Re: 2020 VCAA Biology Exam Solutions
« Reply #11 on: November 18, 2020, 09:22:46 pm »
For 4ai will they accept nucleus as well for Y?
And for 3a, I don't think I specified that lower temperature decreases enzyme activity..I think I just put that optimal temperature has the greatest enzyme-subtrate collisions.. is that fine or did I have to specify lower temperature?

It's unlikely that they'd accept just nucleus, since that's a bit too vague. WRT 3a, since its a 2 mark question, you might get away with that.

What was 11?
The precision, accuracy, reliability, and validity question.

thanks so much man :D so you believe they accept both epidemic and pandemic as long as you give plausible explanation?

Yes, because the passage does not specifically state that measles was present on other continents, but can be plausible if someone on an incoming plane is carrying it so I believe that either would be accepted.

Hey, I'm pretty sure for question 7b u had to be more specific and explain as to why the allele frequency increased more quickly than other mutations or something like that.
Nope, only had to talk about why the frequency increased rapidly. WRT this question, the leading question stem and original question are all irrelevant i.e. don't really influence how you approach this question.
2018: Biology [50 + Prems]
2019: English [46], Latin [45], Chemistry [41], Mathematical Methods [48], Specialist Mathematics [41]
ATAR: 99.95

2020: BMedSci, M.D. @ Monash Uni

VCE Biology Units 1&2 and 3&4 Tutoring for 2021

adgh124

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Re: 2020 VCAA Biology Exam Solutions
« Reply #12 on: November 18, 2020, 10:40:03 pm »
does anyone know the answer to the multiple choice for the one asking what B and T cells have in common? I was so confused between A and D because plasma B cells and cytotoxic T cells don't have immunological memory right?

ezdebebe

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Re: 2020 VCAA Biology Exam Solutions
« Reply #13 on: November 18, 2020, 10:47:43 pm »
It's unlikely that they'd accept just nucleus, since that's a bit too vague. WRT 3a, since its a 2 mark question, you might get away with that.
The precision, accuracy, reliability, and validity question.

Yes, because the passage does not specifically state that measles was present on other continents, but can be plausible if someone on an incoming plane is carrying it so I believe that either would be accepted.
Nope, only had to talk about why the frequency increased rapidly. WRT this question, the leading question stem and original question are all irrelevant i.e. don't really influence how you approach this question.

does that mean i wont get the marks for 7b?
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ezdebebe

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Re: 2020 VCAA Biology Exam Solutions
« Reply #14 on: November 18, 2020, 10:51:41 pm »
does anyone know the answer to the multiple choice for the one asking what B and T cells have in common? I was so confused between A and D because plasma B cells and cytotoxic T cells don't have immunological memory right?

"However, a small portion of long-lived T cells still remains for rapid response upon pathogen re-exposure. This kind of cells is called memory T cells."- quoted from the internet.

So for this question, the answer would be that both b and t cells have an immunological memory.
2020: Biology [39]
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