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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Biology => Topic started by: PhoenixxFire on August 26, 2019, 02:49:38 pm

Title: Feedback thread for self-marked exams
Post by: PhoenixxFire on August 26, 2019, 02:49:38 pm
Hey!

A lot of you will be starting to do past exams soon (don’t worry if you’re not though, I didn’t start until late September). Something that comes up a lot when people start to mark their own exams for the first time is uncertainty over whether they’re marking them correctly/harsh enough/how VCAA examiners mark them.

This thread will hopefully help you to learn how to mark your own exams.
As those of you who have been around the forums for a while will know, we want to help you improve in the most effective way possible – and this often means that we’ll ask you to demonstrate your current understanding so that we know how to help, and that is also true for this thread. Self-marking your exams is a very useful way of learning how to improve your answers, and something I want to encourage you to do, not stop you from doing. For that reason, there are some requirements that you need to meet before you post your exam in this thread, and a few suggestions of what to do after you get feedback on your exam marking.

Requirements for exams posted in this thread:
- Must be VCAA exams (for copyright reasons)
- You must attempt the exam to the best of your ability, obviously that will mean different things to different people, but I don’t want to see any exams that have been rushed through in 20 minutes – you’re not going to learn anything from doing that.
- You must make an attempt at marking it yourself. This doesn’t mean just putting a few ticks in some spots, you need to go through the suggested solutions provided by VCAA and make notes on questions you think you got wrong that include things such as: what else you need to include, what you shouldn’t have included (e.g. through putting a line through part of your answer). You can demonstrate that you’ve done this in any way you want, it just needs to be clear that you have attempted to mark it to the best of your ability before posting it for feedback.

Other suggestions for how to get the most out of exams you complete:
- Mark all exams thoroughly, don’t give yourself a mark if that’s what you meant, give yourself a mark if that’s what you wrote.
- Don’t focus on how many exams you get done, how well you do them is far more important than quantity.
- Rewrite your answers to all questions that you don’t get full marks for with help from the suggested answers to an answer that would give you full marks.
- Keep track of which questions you’re getting wrong and use this information to guide what you need to revise.

How to post your exams:
- Scan your exam (if you don’t have a scanner, there are mobile apps e.g. camscanner that you can use)
- Upload to an external site (e.g. dropbox) and post the link in this thread along with any other comments you want to include (e.g. if there’s some questions you’re particularly unsure about). Please don’t use any link altering websites e.g. tinyurl.

Feel free to send me a message if you have questions/concerns or need help with posting your exam :)
Title: Re: Feedback thread for self-marked exams
Post by: plubbles on October 23, 2019, 12:12:31 am
I really need help.
This is my 10 prac exam I believe,  and I am not improving at all, I think I'm getting worse.
If anyone has advice on how to improve, what to look for in a question, just anything.

And just go over my marking and see what you think. I didn't include any multiple choice, and I crossed some of the questions that weren't relevant.
This is the VCAA 2009 exam 2.

Thank you.

https://www.dropbox.com/s/3wrtyqcrvzxg9r2/Help.pdf?dl=0
Title: Re: Feedback thread for self-marked exams
Post by: darkz on October 23, 2019, 08:13:03 am
I really need help.
This is my 10 prac exam I believe,  and I am not improving at all, I think I'm getting worse.
If anyone has advice on how to improve, what to look for in a question, just anything.

And just go over my marking and see what you think. I didn't include any multiple choice, and I crossed some of the questions that weren't relevant.
This is the VCAA 2009 exam 2.

Thank you.

https://www.dropbox.com/s/3wrtyqcrvzxg9r2/Help.pdf?dl=0

Attached are some corrections. Note: I only looked at questions where you gave yourself marks. Let me know if you have any questions
Title: Re: Feedback thread for self-marked exams
Post by: Bri MT on October 23, 2019, 08:14:27 am
I really need help.
This is my 10 prac exam I believe,  and I am not improving at all, I think I'm getting worse.
If anyone has advice on how to improve, what to look for in a question, just anything.

And just go over my marking and see what you think. I didn't include any multiple choice, and I crossed some of the questions that weren't relevant.
This is the VCAA 2009 exam 2.

Thank you.

https://www.dropbox.com/s/3wrtyqcrvzxg9r2/Help.pdf?dl=0
Welcome to the forums!

Good news: There are some cases where I think you have marked yourself harshly

Some of this I'm not going to give feedback on as I'm not up to speed on what the current bio study design does/n't include and it looks like you may have occasionally gotten this wrong.

Something I would be wary of is circular definitions: e.g. if you were asked what growth is, it's not very useful to say that it's the process of growing
You've done this with part of your answer to 4a

With 4a ii we know it's talking about relative dating using stratigraphy and not absolute dating using isotope dating because it's sedimentary rock. In sedimentary rock you'd expect many of the different particles making it up to have been created at different times and not at the same time as fossilisation, so absolute dating of the rock would be inappropriate

4b ii. VCAA doesn't care too much whether you refer to genetic drift or natural selection but remember that it's unlikely to be 1 selective agent that differentiates them. You'll have random changes (genetic drift) and also a range of differences in selective pressures that will create changes in allele frequencies, until eventually the species are so different that if individuals were brought together from the two populations they would be unable to produce viable offspring.  I doubt they'd penalise you for this but I hope receiving this feedback is useful for your understanding.

5c i isn't your study design so don't stress on that one

5e : all of the DNA samples travel in the same direction in gel electrophoresis - check that you understand the process.

6c cave painting may have lost you the mark in previous years as it would have been considered cultural evolution but iirc you don't need to worry about that. I would say that in general, it's better to do what the question wants (i.e. give 1 example only) than risk it by providing extra.


I think you're doing better than your mark would seem to indicate. At this point, I would try not to focus on the percentage and make sure you're doing quality over quantity. This exam is quite far outside of your study design so even though it's useful practice it's not great as a predictor of your marks.

Good luck!
Title: Re: Feedback thread for self-marked exams
Post by: plubbles on October 23, 2019, 11:57:07 am
Attached are some corrections. Note: I only looked at questions where you gave yourself marks. Let me know if you have any questions

Thank you so much, I didn't even notice that I accidentally used transcription instead of translation, that was really stupid of me. The suggestion for the isolation question was great to!

Welcome to the forums!
Good luck!
haha, thank you.
Wow thank you for this!
I haven't had anyone else look over my practice exams so your analysis of mine is really helpful!
I will probably post another more relevant practice exam so really see where I am at, as these older ones do look for a few different things.
Title: Re: Feedback thread for self-marked exams
Post by: plubbles on October 23, 2019, 06:08:46 pm
I think the best thing for me at the moment is feedback, especially on my expression.

Here is today's attempt:
I really struggled with the fish question, and is the out of Africa hypothesis and the question on neurons irreverent for this study design.

Exam: VCAA 2015
https://www.dropbox.com/s/awie7e5sdq6bi5d/help%202.0.pdf?dl=0
Title: Re: Feedback thread for self-marked exams
Post by: PhoenixxFire on October 23, 2019, 07:27:17 pm
1b - This isn't entirely irrelevant, however many of the suggested answers aren't things you'd be expected to know anymore, which makes it difficult to answer. Your answer is fine given the changes to the study design.

2aii. You're right, this isn't in the study design. All you're expected to know is that neurotransmitters are released from one neuron, diffuse across the synapse, and attach to another.

5b. Your answer is correct, but probably not the best cell to pick because you ended talking about antigen presentation which is part of specific immunity.

6c. This isn't really in the study design anymore. You need to know what translocation mutations are, but this question is more about meiosis.

7c. Don't worry about this question. The suggested answer that VCAA gives is fairly useless and not something that you should be expected to work out.

9cii. You've wasted too much of your space talking about divergence, common ancestors, and naming species indiviudally.
You need to group them by how many differences they have e.g. C, A, & D all have thick limb bones and so are more closely related to each other than they are to B which has thin limb bones. A & D both have thick inner ear bones and so are more closely related to each other than they are to C which has thin inner ear bones.

10aii. Your answer is longer than needed, but correct.

10b. This is also correct, you could shorten it by not mentioning the predators (you can just say they had a selective advantage due to being faster and growing quicker).

11b. This isn't specifically in the study design, however it could come under this dot point
Spoiler
the human fossil record as an example of a classification scheme that is open to interpretations that are contested, refined or replaced when new evidence challenges them or when a new model has greater explanatory power, including whether Homo sapiens and Homo neanderthalensis interbred and the placement of the Denisovans into the Homo evolutionary tree.
It's possible that you could get a question like this on the exam.

fwiw no one gets 100% on vcaa exams (well, some people do, but not many). Assuming you're getting all or almost all of the multiple choice correct, then you're on the border of A/A+ here.
Title: Re: Feedback thread for self-marked exams
Post by: hogp321 on October 23, 2019, 10:37:59 pm
This is my 2017 vcaa sample exam. I'm not entirely sure if my solutions are correct, I've checked with my teachers (corrections are in red pen/blue pen) but I just wanted to confirm a few questions, especially the experimental design ones.
I'm not too sure how harsh i mark myself too so yeah.

Cheers

https://www.dropbox.com/s/l8ufgcn2qzapbo5/new%20doc%202019-10-23%2022.14.57-20191023222614.pdf?dl=0
Title: Re: Feedback thread for self-marked exams
Post by: plubbles on October 24, 2019, 09:43:20 am
1b - This isn't entirely irrelevant, however many of the suggested answers aren't things you'd be expected to know anymore, which makes it difficult to answer. Your answer is fine given the changes to the study design.

2aii. You're right, this isn't in the study design. All you're expected to know is that neurotransmitters are released from one neuron, diffuse across the synapse, and attach to another.

5b. Your answer is correct, but probably not the best cell to pick because you ended talking about antigen presentation which is part of specific immunity.

6c. This isn't really in the study design anymore. You need to know what translocation mutations are, but this question is more about meiosis.

7c. Don't worry about this question. The suggested answer that VCAA gives is fairly useless and not something that you should be expected to work out.

9cii. You've wasted too much of your space talking about divergence, common ancestors, and naming species indiviudally.
You need to group them by how many differences they have e.g. C, A, & D all have thick limb bones and so are more closely related to each other than they are to B which has thin limb bones. A & D both have thick inner ear bones and so are more closely related to each other than they are to C which has thin inner ear bones.

10aii. Your answer is longer than needed, but correct.

10b. This is also correct, you could shorten it by not mentioning the predators (you can just say they had a selective advantage due to being faster and growing quicker).

11b. This isn't specifically in the study design, however it could come under this dot point
Spoiler
the human fossil record as an example of a classification scheme that is open to interpretations that are contested, refined or replaced when new evidence challenges them or when a new model has greater explanatory power, including whether Homo sapiens and Homo neanderthalensis interbred and the placement of the Denisovans into the Homo evolutionary tree.
It's possible that you could get a question like this on the exam.

fwiw no one gets 100% on vcaa exams (well, some people do, but not many). Assuming you're getting all or almost all of the multiple choice correct, then you're on the border of A/A+ here.
THANK YOU! This is amazing feedback, I really appreciate it! I'll take what you said for question 9cii into account, that was a really helpful answer.
Title: Re: Feedback thread for self-marked exams
Post by: PhoenixxFire on October 26, 2019, 12:09:07 pm
This is my 2017 vcaa sample exam. I'm not entirely sure if my solutions are correct, I've checked with my teachers (corrections are in red pen/blue pen) but I just wanted to confirm a few questions, especially the experimental design ones.
I'm not too sure how harsh i mark myself too so yeah.

Cheers

https://www.dropbox.com/s/l8ufgcn2qzapbo5/new%20doc%202019-10-23%2022.14.57-20191023222614.pdf?dl=0
This has been marked well. I don't see any issues with the corrections that have been added.

Try and be more succinct - there are a lot of answers where you've included unnecessary words which is costing you time and space -  you've gone outside the box in a few places, do not do this in the actual exam as anything written outside may not be scanned and may not be visible to your examiners.
Also be careful that you know what the question is asking, this is what's led you astray in a few places for example in 9dii you've said what the promoter is, not what its role is.
Title: Re: Feedback thread for self-marked exams
Post by: ephillips on October 26, 2019, 03:42:15 pm
Just finished the 2017 VCAA exam and I am a bit unsure about some ofmy  responses, so any feedback would be amazing! In particular, I am unsure of my responses to questions  4c and e, 7a, 8, 9a, 10b and 11d. Apologies in advance for my handwriting, it's a lil bit of a mess

Thanks heaps!

https://www.dropbox.com/sh/5cq5zfy2wx1keyd/AACk_iFbGWLlCCIhM9duXqURa?dl=0
Title: Re: Feedback thread for self-marked exams
Post by: paulthekiller123 on October 26, 2019, 05:38:01 pm
Hey this me again, this time its the 2018 nht exam. There's a lot of question I'm unsure about even though I looked at the solutions, I feel like the marking scheme of the assessor's report for nht is a bit off. The marks that I haven't circled in red means that I'm unsure if my answer would suffice any marks at all. Overall, I felt like i did pretty poorly on this exam and I'm not sure if normal VCAA bio exams would be this 'hard', any help would be appreciated :)

https://www.dropbox.com/s/4pizdgebvxkmohg/new%20doc%202019-10-26%2017.16.22-20191026172347.pdf?dl=0
Title: Re: Feedback thread for self-marked exams
Post by: PhoenixxFire on October 26, 2019, 07:03:39 pm
Just finished the 2017 VCAA exam and I am a bit unsure about some of my  responses, so any feedback would be amazing! In particular, I am unsure of my responses to questions  4c and e, 7a, 8, 9a, 10b and 11d. Apologies in advance for my handwriting, it's a lil bit of a mess

Thanks heaps!

https://www.dropbox.com/sh/5cq5zfy2wx1keyd/AACk_iFbGWLlCCIhM9duXqURa?dl=0
1c. The golgi apparatus does alter proteins a bit, but you're not really taught that in VCE so it's possible it wouldn't be accepted.

4c. You've included 2 extra lines at the bottom of the given space which is a pretty good indication that you've written too much. You need to pay attention to how the question is worded - it asks how this form of immunity is beneficial - it doesn't ask why it's beneficial, which is what you've talked about in too much depth by discussing how long it takes for their own immune system to develop. You've then talked a bit about how specific immunity works so it sounds like you didn't really understand what the question wanted. It was worth 3 marks - the marks would have been for saying that it's passive, provides antibodies, and that the joeys own immune system was underdeveloped/insufficient.

4e. Your answer is *almost* detailed enough to get the mark, vcaa did say that they accepted similar answers if good understanding was shown. Your answer was too broad - you don't necessarily need testing to turn that antibiotic into a drug, but you do need testing to turn it into a safe drug.

7a. Probably not the best examples to use - these are both things associated with bipedalism - both homo and Australopithecus were bipedal. Although it's likely that these things were comparatively better adapted for bipedal motion in homo than in Australopithecus, there are other features that would have shown greater difference.

7b. As well as mentioning that homo species appeared prior to 900 000 years prior, you should also mention that australopithicus species had entirely disappeared by then.

8a. Not necessarily before symptoms appear - some genetic conditions have symptoms present at birth. Would be better to say provides information on any genetic conditions the baby has and therefore allows for treatment/prevention.

8b. Your first point is correct, your second point is more of a social implication than an ethical one (although the line between them is quite blurry).

9a. Given it says "in the context given", saying bacteria rather than cell is fine. Your answer is correct.

9bi. You've written too much again, there's no need to restate the stem - you could get rid of most of that first line and just start with "They cut the plasmid..."
You don't need to talk about DNA ligase. You would have just about got the mark just from your first dot point - you just need to add a few more words to say that cutting them with the same enzyme means that the human gene can be inserted.

9bii. Your diagram should look exactly like the one given previously, just with the human gene inserted where the BamH1 recognition site was, and with a BamH1 recognition site at either end of the human gene.

10a. You've got the right idea but you need to be more specific to the scenario eg. say what damage the fire might have done specifically rather than just saying that it damaged the environment (e.g. damaged habitat/resulted in loss of prey).

10b. Your answers for this are fine - too long, but you've included the important information.

11c. Careful with your accuracy/validity. Accuracy is about how close a measurement is to the true value - this part had nothing to do with accuracy, only validity.

11d. What you've written in black isn't really a control - it's a way to improve accuracy, controls are normally about improving validity.
What you've written in blue is correct.
Title: Re: Feedback thread for self-marked exams
Post by: ephillips on October 26, 2019, 08:03:38 pm
1c. The golgi apparatus does alter proteins a bit, but you're not really taught that in VCE so it's possible it wouldn't be accepted.

4c. You've included 2 extra lines at the bottom of the given space which is a pretty good indication that you've written too much. You need to pay attention to how the question is worded - it asks how this form of immunity is beneficial - it doesn't ask why it's beneficial, which is what you've talked about in too much depth by discussing how long it takes for their own immune system to develop. You've then talked a bit about how specific immunity works so it sounds like you didn't really understand what the question wanted. It was worth 3 marks - the marks would have been for saying that it's passive, provides antibodies, and that the joeys own immune system was underdeveloped/insufficient.

4e. Your answer is *almost* detailed enough to get the mark, vcaa did say that they accepted similar answers if good understanding was shown. Your answer was too broad - you don't necessarily need testing to turn that antibiotic into a drug, but you do need testing to turn it into a safe drug.

7a. Probably not the best examples to use - these are both things associated with bipedalism - both homo and Australopithecus were bipedal. Although it's likely that these things were comparatively better adapted for bipedal motion in homo than in Australopithecus, there are other features that would have shown greater difference.

7b. As well as mentioning that homo species appeared prior to 900 000 years prior, you should also mention that australopithicus species had entirely disappeared by then.

8a. Not necessarily before symptoms appear - some genetic conditions have symptoms present at birth. Would be better to say provides information on any genetic conditions the baby has and therefore allows for treatment/prevention.

8b. Your first point is correct, your second point is more of a social implication than an ethical one (although the line between them is quite blurry).

9a. Given it says "in the context given", saying bacteria rather than cell is fine. Your answer is correct.

9bi. You've written too much again, there's no need to restate the stem - you could get rid of most of that first line and just start with "They cut the plasmid..."
You don't need to talk about DNA ligase. You would have just about got the mark just from your first dot point - you just need to add a few more words to say that cutting them with the same enzyme means that the human gene can be inserted.

9bii. Your diagram should look exactly like the one given previously, just with the human gene inserted where the BamH1 recognition site was, and with a BamH1 recognition site at either end of the human gene.

10a. You've got the right idea but you need to be more specific to the scenario eg. say what damage the fire might have done specifically rather than just saying that it damaged the environment (e.g. damaged habitat/resulted in loss of prey).

10b. Your answers for this are fine - too long, but you've included the important information.

11c. Careful with your accuracy/validity. Accuracy is about how close a measurement is to the true value - this part had nothing to do with accuracy, only validity.

11d. What you've written in black isn't really a control - it's a way to improve accuracy, controls are normally about improving validity.
What you've written in blue is correct.

Thank you so much! I struggle a bit with keeping concise so I'll definitely take the feedback on board.
Title: Re: Feedback thread for self-marked exams
Post by: PhoenixxFire on October 26, 2019, 09:22:08 pm
Hey this me again, this time its the 2018 nht exam. There's a lot of question I'm unsure about even though I looked at the solutions, I feel like the marking scheme of the assessor's report for nht is a bit off. The marks that I haven't circled in red means that I'm unsure if my answer would suffice any marks at all. Overall, I felt like i did pretty poorly on this exam and I'm not sure if normal VCAA bio exams would be this 'hard', any help would be appreciated :)

https://www.dropbox.com/s/4pizdgebvxkmohg/new%20doc%202019-10-26%2017.16.22-20191026172347.pdf?dl=0
2b. I think you'd get at least one mark for this.The part you haven't really addressed is the bit about eliminating the infection - just saying that B cells/antibodies can't be produced doesn't really explain why the infection can't be eliminated.

3a. You would have gotten at least 2 marks for this - losing one for not saying it's complementary and maybe losing another for putting the first two points the wrong way around.

5a. You've gotten close to getting both marks, your answer isn't set out very clearly though so it would depend on how carefully your examier was reading/how generous they were feeling. The parts that were worth a mark were were you said that there's "more healthy Th cells that the HIV can infect" and the bit at the bottom that says "there are no more Th cells" - although this isn't exactly true, HIV+ people end up with a lot of immature Th cells because their body is trying to replace them.

5bii. Inflammation doesn't cause high blood pressure - focus on what you know it causes (heat, redness, swelling, increased phagocytes) and then the consequential effect of that.

7a. You might have gotten the mark for your answer, but maybe not because you did need to mention that the presence of a pelvis meant that an ancestor had legs.

8b. Your answer is generally fine but you've gone into too much detail. e.g. you don't need to give examples of selection pressures, it's fine to just say that they're present.

8c. You've over complicated this, make sure you read the question carefully - it told you what you needed to talk about in the stem. For a question like this that's only worth two marks you just need to say how they're determining relatedness (DNA) and what it means (more similar=more related).

9a. Your answer for this is fine, repetition within an experiment is the same thing as having a large sample size.

9f. You probably would have gotten 2 marks for this. You needed to be a bit more detailed about how primers work - that they provide a starting point for the addition of nucleotide bases to create a complementary strand.
Title: Re: Feedback thread for self-marked exams
Post by: paulthekiller123 on October 27, 2019, 03:09:51 pm
This is my 2017 vcaa exam. I put red question marks next to the questions that I don't know if i should receive marks or not. I also took into consideration of writing in the box too haha.

https://www.dropbox.com/s/g7l3w77981cermu/new%20doc%202019-10-27%2014.49.44-20191027145712.pdf?dl=0
Title: Re: Feedback thread for self-marked exams
Post by: PhoenixxFire on October 28, 2019, 12:06:38 pm
This is my 2017 vcaa exam. I put red question marks next to the questions that I don't know if i should receive marks or not. I also took into consideration of writing in the box too haha.

https://www.dropbox.com/s/g7l3w77981cermu/new%20doc%202019-10-27%2014.49.44-20191027145712.pdf?dl=0
2d. You've explained why the signalling molecule might be present and concluded that its presence mean the caterpillars prefer mature leaves - the question is asking about the effect of the signalling molecule - and specifically the effect on the cells of the young leaves, which you haven't answered.

4a. The context for this question isn't really about whether the joey is exposed to pathogens - it's saying the pouch isn't sterile, ie. the pouch isn't free from pathogens.

4e. You're being too general in your answer - the ultimate goal would be to make an antibiotic out of them, but you don't actually need testing for that, you could just chuck them in a drug and hope for the best. You need testing to ensure that they're effective in humans (not a great answer given effectiveness has already been discussed) and to ensure they're safe for humans.

5b. Your answer is fine. It's a bit strange that this is worth 3 marks - given the suggested answers I'd expect it to be worth 2. Be careful how you word things though - you said "without genetic variation" - there will probably still be some variation. Given it is worth 3 marks, I'd probably add two consequences of limited genetic variation rather than just one, even though vcaa doesn't seem to have required that.

6b. Don't use MT as shorthand here, it's not a standard biology term. Other than that, your answer is fine (with the correction of "more closely related" instead of "more recent common ancestor").

8a. Your answer is fine.

8b. The parents consent isn't really relevant - whether or not they're consenting to it isn't an ethical issue, carrying it out if they weren't consenting could be though but there's no indication that they haven't agreed to it. Your second point is a social implication not an ethical one.

9a. Most of your answer is fine, but it's not specifically a DNA molecule, even in this context. That would be like saying "Circular rings of DNA (plasmids) are Dna molecules that transport genes..." - The part about it being DNA is irrelevant because you've already said it's DNA by calling it a plasmid. "circular rings of DNA are a means of transporting genes..." is what the statement is saying. Therefore "vector" is being used to mean "a means of transporting genes..."

9bi. You would've got 1 mark for this. The question specifically asks how they help to insert the gene so you need to say how getting complimentary sticky ends helps.

9bii. You need to include the other genes in this plasmid because otherwise you've just drawn a circle with the human gene - it doesn't show how the human gene fits into this plasmid. You do also need to include the BamH1 recognition sites, it was probably just a mistake that they're not on the vcaa suggested solutions.

9c. You probably would have gotten 2 marks for this - you needed to specify the antibiotic.

It's interesting that for this question vcaa has decided to assume that every plasmid has taken up the human gene - in reality some plasmids would have joined back together without including it and you'd have to separate out those ones - you'd probably do it by growing colonies of each and then putting a bit from each colony onto a plate containing tetracycline - the ones that died had incorporated the human gene and you'd use those and get rid of the colonies of the ones that hadn't died.

However, vcaa said in the stem of the question that "the scientists has carried out the steps required to make plasmids with the inserted human gene", so they're wanting you to assume that all of the plasmids have successfully taken up the human gene - so all you need to do is get rid of the bacteria that didn't take up a plasmid.

I hate this question because this was my exam and I screwed it up haha.

10a. You don't need the first line. You need to be more specific about the consequences of the burning on the land (eg reducing food availability).

10b. Your answers are mostly fine, just be careful about the difference between evidence and justification and that you don't repeat yourself.

11c. It does make the experiment more valid, but that's not specific enough.

11d. Your second point isn't relevant because the temperature is being recorded.

11ei. Your answer is correct.
Title: Re: Feedback thread for self-marked exams
Post by: Guest1121 on October 28, 2019, 12:35:59 pm
Hi, could someone please check my marking of the vaca 2018 practice exam? This is my first post so hopefully I've done this right! I wrote down most of the VCAA answers however I wasn't sure how many marks to award myself for each question. So if someone could please tell me how many marks each one is worth that would be amazing! Thanks!

https://www.dropbox.com/s/fcfcsuixxmsrs9z/Scan%20Mietta%2010.pdf?dl=0
Title: Re: Feedback thread for self-marked exams
Post by: PhoenixxFire on October 29, 2019, 11:49:49 am
Hi, could someone please check my marking of the vaca 2018 practice exam? This is my first post so hopefully I've done this right! I wrote down most of the VCAA answers however I wasn't sure how many marks to award myself for each question. So if someone could please tell me how many marks each one is worth that would be amazing! Thanks!

https://www.dropbox.com/s/fcfcsuixxmsrs9z/Scan%20Mietta%2010.pdf?dl=0
1a. For your second line, call it a ribosome, not rRNA (a ribosome is made up of both rRNA and protein). Also mRNA has codons not triplets - triplets are on DNA.
You can get rid of the last line entirely - there are other steps that happen after translation for tryptase to form. Replace it with something like "when the ribosome reaches a stop codon, translation ends and the polypeptide is released."

4c. Don't call the toxin a pathogen. A pathogen is a disease causing agent - this doesn't cause disease.

6b. You've just repeated information given in the stem of the question for this. Make sure you're actually providing new information.

7a. A gene being recessive isn't the only reason it wouldn't be present in the whole population. You should probably have worded this differently - eg. saying that individuals can carry a gene and pass it down to their offspring without that gene effecting their own phenotype.

8b. The bit about preventing the DNA production of folic acid is a bit confusing - you should have said that the lack of active folic acid reduces dna production which slows cell growth because cell growth requires dna production.

8c. You only need to include one of the answers (either not suitable with reason or maybe suitable with reason), not both. You don't need to explain when an autoimmune disease occurs - just need to say that it is autoimmune and therefore antibiotics wouldn't work because they only work on bacteria.

10c. Reduced genetic diversity may have been accepted but you'd probably have to be more specific. eg. reduced genetic diversity of rice due to this strain becoming prevalent. Even then, there isn't heaps of diversity to farmed rice anyway because it's undergone artificial selection.

11b. Time is part of the dependent variable so it's not controlled.

11d. The hypothesis is that the red algal balls will photosynthesis faster than the green ones - so results contradictory to this would refute the hypothesis, either the green balls photosynthesising faster or at equal rate to the red balls.

11e. It's a negative control (a positive control would be white light). It's not about being able to compare them - it's to make sure the results are valid (that the colour change is actually due to photosynthesis).

For the questions I haven't commented on, your own corrections are fine. Your marking is also fine for the most part (whether some of your answers were accepted may have depended on the examiner/you may have gotten the mark from one examiner but not both).
Title: Re: Feedback thread for self-marked exams
Post by: plubbles on October 29, 2019, 05:33:38 pm
It's me again!
Guess what, i'm still not improving.
I know what the questions were, but for some reason, I either didn't know how to answer them, left a thing or two out, misinterpreted the question....

I would take any advice you can give me. I am kind of desperate.
Thank you!
2018 NH VCAA exam
https://www.dropbox.com/s/y62b8pnvh4jxrd7/2018%20NH%20VCAA%20Exam.pdf?dl=0
Title: Re: Feedback thread for self-marked exams
Post by: Bri MT on October 29, 2019, 06:34:53 pm
It's me again!
Guess what, i'm still not improving.
I know what the questions were, but for some reason, I either didn't know how to answer them, left a thing or two out, misinterpreted the question....

I would take any advice you can give me. I am kind of desperate.
Thank you!
2018 NH VCAA exam
https://www.dropbox.com/s/y62b8pnvh4jxrd7/2018%20NH%20VCAA%20Exam.pdf?dl=0

I don't have time to do detailed feedback as I'm heading off to a meeting but:
- There are times when you aren't giving yourself the marks because you didn't use the same words as VCAA but your answer is till valid
- Have you experimented with your timing strategy? I found that getting that down helped me make less silly errors.


Question 8e. Look at the order of speciation. Based on this, we do not expect that the most recent common ancestor for each of the islands was canopy dwelling. Additionally, we do not expect there to have been significant gene flow between the island populations. This suggests that on each of the four islands characteristics suitable for living in a canopy environment evolved separately.

Remember that controls act as baselines against which the impact of the IV may be compared

Good luck!
Title: Re: Feedback thread for self-marked exams
Post by: Guest1121 on October 30, 2019, 07:12:56 pm
thank you so much!



1a. For your second line, call it a ribosome, not rRNA (a ribosome is made up of both rRNA and protein). Also mRNA has codons not triplets - triplets are on DNA.
You can get rid of the last line entirely - there are other steps that happen after translation for tryptase to form. Replace it with something like "when the ribosome reaches a stop codon, translation ends and the polypeptide is released."

4c. Don't call the toxin a pathogen. A pathogen is a disease causing agent - this doesn't cause disease.

6b. You've just repeated information given in the stem of the question for this. Make sure you're actually providing new information.

7a. A gene being recessive isn't the only reason it wouldn't be present in the whole population. You should probably have worded this differently - eg. saying that individuals can carry a gene and pass it down to their offspring without that gene effecting their own phenotype.

8b. The bit about preventing the DNA production of folic acid is a bit confusing - you should have said that the lack of active folic acid reduces dna production which slows cell growth because cell growth requires dna production.

8c. You only need to include one of the answers (either not suitable with reason or maybe suitable with reason), not both. You don't need to explain when an autoimmune disease occurs - just need to say that it is autoimmune and therefore antibiotics wouldn't work because they only work on bacteria.

10c. Reduced genetic diversity may have been accepted but you'd probably have to be more specific. eg. reduced genetic diversity of rice due to this strain becoming prevalent. Even then, there isn't heaps of diversity to farmed rice anyway because it's undergone artificial selection.

11b. Time is part of the dependent variable so it's not controlled.

11d. The hypothesis is that the red algal balls will photosynthesis faster than the green ones - so results contradictory to this would refute the hypothesis, either the green balls photosynthesising faster or at equal rate to the red balls.

11e. It's a negative control (a positive control would be white light). It's not about being able to compare them - it's to make sure the results are valid (that the colour change is actually due to photosynthesis).

For the questions I haven't commented on, your own corrections are fine. Your marking is also fine for the most part (whether some of your answers were accepted may have depended on the examiner/you may have gotten the mark from one examiner but not both).