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July 16, 2019, 11:59:47 am

Author Topic: VCE Biology Question Thread  (Read 1259336 times)  Share 

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Qwerty1234qwerty

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Re: VCE Biology Question Thread
« Reply #10815 on: October 14, 2018, 10:51:09 am »
0
Whatís the difference between a primate and Hominoid? Thanks

Owlbird83

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Re: VCE Biology Question Thread
« Reply #10816 on: October 14, 2018, 10:59:40 am »
+2
Whatís the difference between a primate and Hominoid? Thanks

Primates is the order and is a broader classification, and homonoids is the superfamily, containing great apes and humans.
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PhoenixxFire

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Re: VCE Biology Question Thread
« Reply #10817 on: October 14, 2018, 11:12:04 am »
+3
Describe the out of Africa hypothesis:
- Homo Erectus migrated out of Africa and spread across the world
- Homo sapiens evolved from a hominin population in Africa and then migrated out of Africa

Describe the multi regional hypothesis:
- Homo Erectus migrated out of Africa and different populations of Homo Erectus became genetically isolated from each other
- Homo sapiens simultaneously evolved from different populations of Homo Erectus around the world

What else could I include in the above explanations if it was a 3-4 mark question?
I doubt you'd get a 3 or 4 mark question on this, what you've said is really all you have to know about it. If you did it would probably be a compare question and you'd have to talk about both theories.
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PopcornTime

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Re: VCE Biology Question Thread
« Reply #10818 on: October 14, 2018, 01:15:41 pm »
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Why does natural selection act on phenotypes?

What methods should we learn for identifying pathogens on the exam?

What should we know about emerging diseases for the exam?

What should we know about types of treatments for pathogens for the exams?

Why is the answer TWO copies for this question?

MOD EDIT: Merged double post
« Last Edit: October 14, 2018, 01:26:04 pm by Sine »

Owlbird83

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Re: VCE Biology Question Thread
« Reply #10819 on: October 14, 2018, 02:05:05 pm »
+2

Why is the answer TWO copies for this question?



Because you have two copies of each chromosome in all of your body cells, one from your mum and one from your dad they are all 2n, diploid. So there would be the gene locus on each of the chromosome 1.
« Last Edit: October 14, 2018, 02:07:36 pm by Owlbird83 »
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PhoenixxFire

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Re: VCE Biology Question Thread
« Reply #10820 on: October 14, 2018, 02:46:02 pm »
+4
1. Why does natural selection act on phenotypes?

2. What methods should we learn for identifying pathogens on the exam?

3. What should we know about emerging diseases for the exam?

4. What should we know about types of treatments for pathogens for the exams?
1. Natural selection is based off how well an individual can survive/reproduce in an environment. It's ability to survive is determined by the traits it has. A phenotype is the traits an individual possesses. Therefore natural selection acts on phenotypes. It doesn't matter whether an individual is heterozygous or homozygous for a trait, it just matters if they have the trait or not.

2. Just going to steal this answer on this from last year because I don't know a whole lot about identifying pathogens.

There are actually a few ways to identify a pathogen (bacteria or virus, in this case)
Bacteria:
- agglutination test (with specific antibodies)
- precipitation test (to see if a bacterial colony precipitates in the blood of an infected person)
- Western blot test (used to separate and identify proteins specific to a bacteria)
- ELISA (enzyme-linked immunosorbent assay, which is used to detect and count substances such as antibodies, hormones, enzymes and antigens, which indicates the type of bacteria we might be looking for)

Virus (these things are smaller, so we have to use more precise techniques to kinda sort them out)
-ELISA
- X-ray crystallography (which is used to determine the atomic and molecular structure of crystals, can be used to identify viruses of specific shapes and sizes)
- Electron microscope (these things let you see really small things so you can see viruses with this)

3.
Spoiler
ē    strategies that deal with the emergence of new diseases in a globally connected world, including the distinction
between epidemics and pandemics, the use of scientific knowledge to identify the pathogen, and the types of
treatments
My interpretation of this is that you don't need to actually know about emerging diseases as such, you just need to know about how to identify pathogens and treatment options.

4. Just need to know about antibiotics/antivirals/etc. including what type of pathogen they can be used against.
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Azim.m

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Re: VCE Biology Question Thread
« Reply #10821 on: October 15, 2018, 05:15:29 am »
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The examiners report states that the sequence of nucleotides could be determined.

Could I also say it provides scientists information about the proteins produced by the organism (virus in this case)?

PopcornTime

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Re: VCE Biology Question Thread
« Reply #10822 on: October 15, 2018, 10:05:35 am »
+3
The examiners report states that the sequence of nucleotides could be determined.

Could I also say it provides scientists information about the proteins produced by the organism (virus in this case)?

Its probably better to say sequence of nucleotides could be determined.

As it is the sequence of nucleotides that is involved in protein synthesis. So think big picture before going more specific!

peachxmh

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Re: VCE Biology Question Thread
« Reply #10823 on: October 15, 2018, 04:14:35 pm »
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Hey guys, just gonna word-vomit a few questions here because these are areas that I've been consistently getting confused about in practice exams, and I haven't found much information online or in my textbook that was helpful:

1. Are there other regulatory genes that regulate BMP4 genes? My teacher said that BMP4 genes are the top of the hierarchy and thus there are no genes that control it, but how would BMP4 gene be regulated then? (as in how much, when, location, etc.) I also read somewhere on atarnotes where someone said that regulatory genes control BMP4 genes and that mutations occur in these regulatory genes, affecting its expression, so I'm a little confused. With regards to BMP4 as well, I don't think my definition of it is adequate/clear enough, so could someone tell me what I should add or change?: BMP4 is a master gene that produces BMP4 signalling molecule which switches on genes required for cellular differentiation in embryonic (stem?) cells to produce the specific structures of an organism

2. With allopatric speciation, is it accurate to say that there was variation in a population which allowed them to colonise different habitats, and that after they were separated by a geographical barrier, no gene flow occurred and they accumulated mutations due to the different selection pressures in their respective environments, leading to the inability to create viable, fertile offspring? Would this lead to a change in allele frequencies but not gene pool because the alleles are still present, it's just that the alleles correlating to the favourable trait have increased in proportion over other alleles?

3. In the Out of Africa theory, did H.sapiens evolve from H.erectus or H.heidelbergensis? Is it true to say that some H. erectus and H. heidelbergensis populations stayed in Africa to give rise to H.sapiens, while other populations of H.erectus and H.heidelbergensis migrated elsewhere in the world? And that the H.heidelbergensis then evolved into Neanderthals and Denisovans whilst the H.erectus just... died out? (taking a wild guess here hey)

4. Final question lol! I recently did the 2017 exam (and found it much harder than the previous ones :( ), did VCAA change the format of Bio exams? It seemed quite different in style to the other previous exams (esp. that 6(?) marker question on megafauna)

Edit: Forgot to mention - in radiometric dating, is it the RATIO of the isotopes that is being measured and used to determine the age of a fossil/rock or is it just the amount of an isotope (e.g. in potassium-argon dating, is it the ratio of Potassium-40 to Argon-40 that is being measured and compared to the ratio in new rock, or just the amount of Potassium-40 or Argon-40 created (and no ratio is looked at?) idk if that makes any sense haha
« Last Edit: October 15, 2018, 04:55:02 pm by peachxmh »
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C14M8S

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Re: VCE Biology Question Thread
« Reply #10824 on: October 15, 2018, 06:20:08 pm »
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Just a few more questions to add to the vomit-pile -

1) Are post-transcriptional modifications done in the Rough ER or in the golgi body? This has been confusing me, I've gotten various solutions from exams.
2) How much detail is required about post-transcriptional modifications? I've not seen it in the study design.
3) Are cell membrane receptors classed as proteins or glycoproteins, or are both capable of being receptors? Again I've gotten conflicting responses.
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PhoenixxFire

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Re: VCE Biology Question Thread
« Reply #10825 on: October 15, 2018, 06:58:59 pm »
+4
Quote
1. Are there other regulatory genes that regulate BMP4 genes? My teacher said that BMP4 genes are the top of the hierarchy and thus there are no genes that control it, but how would BMP4 gene be regulated then? (as in how much, when, location, etc.) I also read somewhere on atarnotes where someone said that regulatory genes control BMP4 genes and that mutations occur in these regulatory genes, affecting its expression, so I'm a little confused. With regards to BMP4 as well, I don't think my definition of it is adequate/clear enough, so could someone tell me what I should add or change?: BMP4 is a master gene that produces BMP4 signalling molecule which switches on genes required for cellular differentiation in embryonic (stem?) cells to produce the specific structures of an organism
BMP4 is a regulatory gene that regulates the expression of Bone Morphogenic Protein 4 (also called BMP4)

So mutations in the regulatory gene BMP4 alter the expression of the protein BMP4. It gets super confusing because theyíre both called BMP4, but the mutations occur in the regulatory gene BMP4.

Quote
2. With allopatric speciation, is it accurate to say that there was variation in a population which allowed them to colonise different habitats, this bit is unneccary and that after they were separated by a geographical barrier, no gene flow occurred and they accumulated mutations due to the different selection pressures in their respective environments, leading to the inability to create viable, fertile offspring? Would this lead to a change in allele frequencies but not gene pool because the alleles are still present, it's just that the alleles correlating to the favourable trait have increased in proportion over other alleles?
-Population seperated by geographic barrier
-Populations evolve independently due to different selection pressures/different mutations accumulating
-Populations are so different that they are unable to interbreed (they are different species)

-would lead to changes in gene pool, alleles could be completely removed from population if they become unfavourable or due to genetic drift.

Iím not ignoring the other questions, Iíve got to go back to work! Will get to them later tonight if someone doesnít beat me to it - I encourage all of you current bio students to have a try at answering them if you think you can - it doesnít matter if you get it wrong, just give it a try :)
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juntyhee

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Re: VCE Biology Question Thread
« Reply #10826 on: October 15, 2018, 07:34:23 pm »
+7
Just a few more questions to add to the vomit-pile -

1) Are post-transcriptional modifications done in the Rough ER or in the golgi body? This has been confusing me, I've gotten various solutions from exams.
2) How much detail is required about post-transcriptional modifications? I've not seen it in the study design.
3) Are cell membrane receptors classed as proteins or glycoproteins, or are both capable of being receptors? Again I've gotten conflicting responses.

1. Good question, in reality modifications occur in both the ER and golgi. For VCE, I like to think of the ER as where the polypeptide chain is folded into its secondary, tertiary, etc structures while the Golgi is primarily where actual modification of the protein occurs (though note that adding of sugars also do occur in the rough ER).

2. Just know introns are removed while exons are joined, Methyl Cap added to 5' and Poly-A-Tail added to 3'. Also know that this does not occur in prokaryotes, hence why prokaryotic mRNA is usually unstable due to the lack of these structures AND they generally have a proteome that isn't as diverse due to alternative splicing not occurring.

3. Given the nature of biology i'm sure they are circumstances where both act as receptors. But i'd say glycoproteins act primarily for cellular recognition and communication, while receptors fall under the general 'protein' category. Doubt you'd have to know this though.
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C14M8S

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Re: VCE Biology Question Thread
« Reply #10827 on: October 15, 2018, 07:39:20 pm »
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How deep of an understanding do we need of post-translational modificatations? I haven't seen them on the syllabus either, but they've appeared on a few practice exams.
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PhoenixxFire

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Re: VCE Biology Question Thread
« Reply #10828 on: October 16, 2018, 12:12:16 am »
+4
Quote
3. In the Out of Africa theory, did H.sapiens evolve from H.erectus or H.heidelbergensis? Is it true to say that some H. erectus and H. heidelbergensis populations stayed in Africa to give rise to H.sapiens, while other populations of H.erectus and H.heidelbergensis migrated elsewhere in the world? And that the H.heidelbergensis then evolved into Neanderthals and Denisovans whilst the H.erectus just... died out? (taking a wild guess here hey)
Iím not really too sure on this (sorry!)- itís not something I paid much attention too. All Iíve got in my notes is that H sapiens evolved in Africa and then moved out, replacing H. Erectus and H. Ergaster populations that were already in other parts of the world, but that doesnít really answer any of your questions haha

Quote
4. Final question lol! I recently did the 2017 exam (and found it much harder than the previous ones :( ), did VCAA change the format of Bio exams? It seemed quite different in style to the other previous exams (esp. that 6(?) marker question on megafauna)
Yep. Itís changed to focus on experimental design a lot more, definitely expect to see that again this year. I have no idea what that six-marker was about. My thought process at the time was along the lines of Ďwtf why is there reading comprehension in my bio examí. Having said that, to be able to understand it you had to understand the biological concepts behind it so it was actually a really interesting question.

Quote
Edit: Forgot to mention - in radiometric dating, is it the RATIO of the isotopes that is being measured and used to determine the age of a fossil/rock or is it just the amount of an isotope (e.g. in potassium-argon dating, is it the ratio of Potassium-40 to Argon-40 that is being measured and compared to the ratio in new rock, or just the amount of Potassium-40 or Argon-40 created (and no ratio is looked at?) idk if that makes any sense haha
Itís the ratio

Quote from: C14M8S
1) Are post-transcriptional modifications done in the Rough ER or in the golgi body? This has been confusing me, I've gotten various solutions from exams.
For this did you mean post transcriptional or post translational?
Post transcriptional occurs in the nucleus, post translational is as juntyhee has said above.

Quote
How deep of an understanding do we need of post-translational modificatations? I haven't seen them on the syllabus either, but they've appeared on a few practice exams.
Donít really need to know anything about them. They occur and can result in proteins with different functions (may not even need to know that much). Did you see it on commercial papers or old VCAA exams?
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persistent_insomniac

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Re: VCE Biology Question Thread
« Reply #10829 on: October 16, 2018, 06:50:57 am »
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Does RNA processing/post-transcriptional modifications happen in prokaryotes like bacteria? I thought it didn't but some practise exams are saying it does?
Also would be it useful to do the old VCAA exams (2002 - 2012) or would it be a waste of time?
Thanks!