VCE Biology Question Thread

[PhoenixxFire]

1) How much ATP is formed during the light-dependant phase of photosynthesis? Do I need to know this for the context of VCE?
2) What structural differences occur between leaves exposed to low light intensity compared to high light intensity? I'm assuming that leaves exposed to higher light levels have leaves with a brighter green tint due to having more chloroplasts.
3) What is the difference between a polypeptide and a protein?
4) For the context of VCE, do I need to know about the light-independent phase producing G3P?

1) Don’t need to know.

2) Don’t need to know this either but yes you’re correct.

3) A polypeptide is a chain of amino acids. A protein can be made of one or more polypeptide chains.

4) Nope

[vox nihili]

Identify an issue that would make scientists cautious about using gremlins gene therapy

Would it be correct to say that the modified germ line cell of the therapy could be deleterious and be passed down to offsprings of the treated individual?

yep this is reasonable

EDIT: be careful about how you phrase your answer to this though. The germ cell doesn't get passed down. Remember the germ line effectively refers to sperm and eggs, so this is what is being fixed.

EDIT EDIT: my phrasing here also leaves somewhat to be desired but I'm going with the it's too early in the morning excuse :p

1). I’m not really sure what they want here (gotta love assessors reports ) From what they’ve written on the assessors report I don’t think they’re after an answer that specific. I think you’d be right if you wrote anything about how they’re swollen because of the virus (I’m kind of just guessing, but I don’t think they’d want a specific reason). Maybe send Vox Nihili a msg and ask if he knows. He’s probably really busy atm but he might be able to explain it.

Also - people who are posting questions in the middle of the night, please sleep instead. Getting an extra practice exam done isn't worth the effects of sleep deprivation

2006 E1Q8C wasn't VCAA's best work tbh. If the lymph nodes are swollen, there's an immune response to something (in this case HIV). I think that's pretty much what they wanted you to say in response to that question: "swelling of the lymph nodes indicates that there is an ongoing immune response to HIV through 2-5 years inclusive". PF is absolutely right in saying that you certainly don't need to go to any level of detail.

This question came at a time when HIV wasn't on the course, so the expectations might be a little different in the current course. All of the information relevant to that question was in the graph on the page. The immune system initially mounts a pretty good response against HIV, which sees viral levels fall. Eventually, however, the remaining HIV picks away at the T-helper cells and starts to grow up again. Then you see a rise in HIV levels and an inversely proportional fall in T-helper cells.



Second that you should be putting sleep first. An absolute priority during the preparation for the exams should be trying to get a good routine of sleep. Your days will be more productive and, critically, that productivity will be more useful. I'm sure all of you are getting plenty done by way of practice exams etc, but your score isn't determined by the number of practice exams you do but rather by their use to their learning. A practice exam done sleep deprived is useless. Get some sleep!

[M-D]

VCAA 2015 Exam Question 23 (MCQ)

What is the difference between options A and C? Aren't they both the same?

[Robot10]

VCAA 2015 Exam Question 23 (MCQ)

What is the difference between options A and C? Aren't they both the same?

They’re not the same
Option A When transcribed TCG(last triplet) is AGC which codes for amino acid: Ser

Option C:When transcribed TCT(last triplet) is AGA which codes for amino acid: Arg

I’ve also got a few questions. See attached PDF.

For 5b. Would it be correct to say The chemical code is composed of DNA and humans may have the same allele causing the CHS disorder

Also For qn 6d, What does technological evolution refer to I’m also unsure of what the qn is asking.

Thanks

[PhoenixxFire]

5d. I think it’d be important to mention that it means that the allele has the same genetic sequence or words to that effect rather than just say that it’s the same allele.

6d. So technological evolution is the evolution of technology from primitive tools to things like computers. Cultural evolution is the passing on and accumulation of knowledge. So the passing on of information from one generation to the next has allowed for technological evolution because of learning. If every individual had to learn how to make a sharp rock themselves then they wouldn’t have time to figure out anything else, but if they get taught how to make a sharp rock (cultural evolution) then they can figure out how to make better rocks (technological evolution) and then they can pass that information onto the next generation and so on.

[napkin101]

Do we need to know the exact number of ATP/ADP +Pi and NADPH/NADP+ that go into/come out of the light dependent and independent stages of photosynthesis?

[PhoenixxFire]

Do we need to know the exact number of ATP/ADP +Pi and NADPH/NADP+ that go into/come out of the light dependent and independent stages of photosynthesis?

Nope

[persistent_insomniac]

Why would scientists want to use non-coding regions that are hypervariable when comparing individuals?
Is it because mutations in non-coding regions will be passed on to the next generation because they do not harm the organism?

[PhoenixxFire]

Why would scientists want to use non-coding regions that are hypervariable when comparing individuals?
Is it because mutations in non-coding regions will be passed on to the next generation because they do not harm the organism?

Yeah basically. As you've said they're hypervariable - so it's less likely that two individuals will have matching non-coding regions. The reason they're hypervariable is because selection pressures don't act on them.

[galaxy21]

Hi. I just did the attached question in a practice exam and I am a little confused. I had selected A - Cofactor, however originanlly had selected B - Coenzyme. B is the correct answer. However isn't a coenzyme a type of cofactor? I had changed my answer based on this, as cofactor would have been a more general term, and I wasn't 100% sure whether there was types of cofactors,other than coenzymes, that are organic.
The solutions, however, say that all cofactors are inorganic. Is this right?
Thank you!

[vox nihili]

Hi. I just did the attached question in a practice exam and I am a little confused. I had selected A - Cofactor, however originanlly had selected B - Coenzyme. B is the correct answer. However isn't a coenzyme a type of cofactor? I had changed my answer based on this, as cofactor would have been a more general term, and I wasn't 100% sure whether there was types of cofactors,other than coenzymes, that are organic.
The solutions, however, say that all cofactors are inorganic. Is this right?
Thank you!

I agree with you that this is an unreasonable question, because two of the answers are technically correct. There is a tendency among university level exams to ask students to indicate the "most correct" answer—it appears as though the authors of this exam have met it with that expectation.

[PopcornTime]

What are some good photosynthesis experiments we should know about?

Any tips for expression when answering questions?

[PhoenixxFire]

1. What are some good photosynthesis experiments we should know about?

2. Any tips for expression when answering questions?

1. Don’t need to know any

2. Be clear. The way I think of it is that you need to just say what you want to say clearly and succinctly - don’t include unnecessary information. This partly comes down to knowing what the question wants and just giving them that.

[galaxy21]

Hi,
Just wondering, what level of detail do we need to know about the timeline of events in evolution? What key events do we need to know for the exam?

[vox nihili]

Hi,
Just wondering, what level of detail do we need to know about the timeline of events in evolution? What key events do we need to know for the exam?

No one is really sure tbh, as there haven't been any questions about this in the past. I'm not as across this particular part of the course, so have no thoughts myself. Any advice you get here should be taken with some skepticism just because of the lack of information out there.