ATAR Notes: Forum
Archived Discussion => Science Exams => HSC Exam Discussion 2017 => Results => New South Wales => Biology Exam Discussion => Topic started by: naomisirmai on October 25, 2017, 10:59:58 am
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Hey all!
Congratulations on finishing Bio!! Huge!
What did you think of the exam? Let me know below!
OVERALL THOUGHTS: Overall a fair exam. They tested your understanding of a whole lot of concepts, which will have rewarded you if you'd studied a bit of everything! A few questionable MCQs, and a tricky 8-marker at the end - like always, a combination of the work of scientists + new technology.
MCQs:
1. C (homeostasis)
2. D (nervous)
3. D (frank macfarlane burnet)
4. A (they fight infection)
5. B (comparative anatomy)
6. C (phagocytosis)
7. A (urea)
8. C (pH decreases, acidity increases)
9. B (experiment = 5mL starch + 1mL amylase, control = 5mL starch)
10. B (10µm - I don't have a ruler pls take this with a grain of salt.
11. C (both T and B cells have ways of recognising antigens)
12. B (Tt x tt)
13. D (a tricky one! could have been A or D, depending on how you interpreted the wording "newly made strand")
14. C (fungi have cell walls, protozoans are unicellular and do not)
15. D (codominance)
16. B (osmosis is a passive process of water moving from high to low concentrations)
17. A (Rosalind Franklin discovered DNA’s double helix shape)
18. C (accuracy = proximity of findings to theoretical findings)
19. A (44 chromosomes/2 + 62 chromosomes/2 = 53 overall. Tricky and IMO not in the syllabus)
20. D (the concentration of the substrate is decreasing)
SAQ:
21. Enzyme diagram
A = enzyme, B = substrate (substrate is destroyed, enzyme remains) (2m)
22. The disease question. (6m)
a. Examples of infectious/non-infectious disease. You’d have your own examples here. ˝ a mark for each part of the table.
b. Drinking water question (4m). Just pick two examples and explain how they reduce risk of infection
- Chlorine +- ammonia added to drinking water in order to kill/deactivate microbes, leaving a residue that prevents recontamination
- pH adjusted with lime and caustic soda to create an inhospitable environment for certain pathogens.
23. The blood vessel question (5m)
- Vessel 1 = artery: thick muscular walls allow them to push oxygenated blood at high pressures from the heart to tissues in need.
- Vessel 2 = vein: valves to prevent backflow of deoxygenated blood to tissues – allowing it to travel to the lungs for re-oxygenation.
24. Genes and homologous chromosomes (7m)
a. Crossing over (2m)
i. Before: Aa Bb Gg
ii. After: Aa Bb GG and Aa Bb gg
b. Effect of independent assortment on the genotype of the offspring (2m)
Define independent assortment then quickly explain that it means that those chromatids could be sorted with any combination of genes from other chromosomes
c. Isolation and evolution (3m)
I would have defined evolution in a nice quick sentence, and explained how geographic isolation allows that population to evolve specific adaptations best suited to their unique environment
25. Urine concentration of marine fish and freshwater fish (4m)
I would have drawn a table here.
- Marine fish = surrounded by salt water = lose water to their environment = very concentrated urine to maintain a steady state.
- Freshwater fish = surrounded by fresh water = gain water from their environment = very dilute urine to maintain a steady state.
26. Substrate/enzyme question (4m)
a. Independent variable = substrate concentration
b. Trends: as substrate concentration increases, so does the rate of reaction. Eventually a plateau is reached. This is because the enzymes’ active sites are saturated and reactions cannot be catalysed at a faster rate.
27. Plants question (5m)
a. Transverse sections of xylem and phloem. Something you would have wrote-learned.
b. Transport of sugars through a plant: ‘Pressure flow theory’: sugars are loaded actively into the ‘source’, and water follows by diffusion. This allows the sugars to move passively by diffusion to areas of the plant in need – the ‘sink’ – where they are actively unloaded.
28. PENDING! The photocopy of the exam I received was missing this page.
29. 'Justify the change in emphasis from treatment to prevention of a named disease’ (5m).
You could have named any disease – ideally one with some good methods of prevention! Vaccines etc.
You then had to explain why this change was beneficial. The answer is pretty much the same for any disease; prevention addresses problems before they occur (allowing for greater quality of life in the population), saves the government and individuals money (public health programs for prevention are much cheaper than treating patients), and prevention – particularly in the case of vaccine-preventable diseases - allows for herd immunity which protects the vulnerable.
30. Immune response question (6m)
a. The role of ONE T-cell (2m)
eg. Suppressor T-cells; to suppress the immune response once the antigen is cleared.
b. Benefit/limitation of immunosuppression in organ transplant patients (4m)
eg. BENEFIT: prevents organ ‘rejection’ when the implanted organ is recognised by the body’s immune cells as foreign and lodges an immune response against it
LIMITATION: renders the patient vulnerable to all infectious diseases, as their immune response must be suppressed for the rest of their life.
31. ‘Assess the importance of the work of Beadle and Tatum to the ability to produce a specific transgenic species’ (8m)
So your job here is to:
1) explain what the work of Beadle and Tatum was, and its significance
2) define transgenic species
3) name a specific transgenic species and give about a sentence of detail about it
4) link the two; explaining where Beadle and Tatum’s findings come into play and ‘assessing’ their importance. Here I’d say ‘very’. It is possible to argue that there were other significant scientists also. You can have named them in addition to discussing B + T.
5) Have some kind of concluding statement.
As a rough guide:
Beadle and Tatum applied controlled mutation by UV rays to neurospora crassa (bread mould) – finding that mutations to specific genes resulted in the mould being unable to produce specific proteins. They therefore concluded that one gene is responsible for the production of one protein (later amended to one polypeptide).
Transgenic species are species that contain inserted genetic material that is not normally present, for example – ‘Cold Strawberries’ contain a gene from salmon that allows them to survive the cold.
Beadle and Tatum’s work was clearly extremely significant in the origination of transgenic species; which exist on the premise that inserting specific genes will lead to the production of specific, desired proteins. The example of Cold Strawberries requires an understanding of the characteristic desired, the protein that facilitates that characteristic, and the genes that code for that protein – all derivatives of Beadle and Tatum’s findings.
Clearly, the work of other scientists was also significant. For example, the structure and nature of DNA – discovered largely by Franklin, Watson, Crick and Chargaff – is important too.
Beadle and Tatum’s work built on the findings of scientists before them; using new technology available to them. The same is true for the creation of transgenic species; the creators of which built on the findings of Beadle and Tatum, along with other scientists. An understanding and appreciation of the work of others is essential for new discoveries in biology.
And... that's it! Great job team!! Hopefully you've got the time to give yourself a well-deserved break.
If you'd like to join in the discussion but don't have an account - you can make one right here and it'll take you less than a minute.
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It was easier than expected tbhh
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yeah, i think it wasnt too bad
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Pretty good
Genetics option was absolutely amazing
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Wrote a whole page on the use of highly variable genes, and it was only 3 marks kek
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Hey all!
Congratulations on finishing Bio!! Huge!
What did you think of the exam? Let me know below!
I'm working on the suggested answers to the paper now, and I'll update this thread with them soon.
OVERALL THOUGHTS: Coming soon!
MCQs:
1. C (homeostasis)
2. D (nervous)
3. D (frank macfarlane burnet)
4. A (they fight infection)
5. B (comparative anatomy)
6. C (phagocytosis)
7. A (urea)
8. C (pH decreases, acidity increases)
9. B (experiment = 5mL starch + 1mL amylase, control = 5mL starch)
10. C (I don’t have a ruler but my educated guess says it’s a white blood cell which is 12µm in diameter)
11. D (B cells form clones, T cells do not)
12. B (Tt x tt)
13. A (DNA -> DNA keeps the same sequence. RNA not mentioned. A tricky one!)
14. C (fungi have cell walls, protozoans are unicellular and do not)
15. D (codominance)
16. B (osmosis is a passive process of water moving from high to low concentrations)
17. A (Rosalind Franklin discovered DNA’s double helix shape)
18. C (accuracy = proximity of findings to theoretical findings)
19. A (44 chromosomes/2 + 62 chromosomes/2 = 53 overall. Tricky and IMO not in the syllabus)
20. D (the concentration of the substrate is decreasing)
SAQ: Coming soon!
Q 10 think it's 10 um because the scale was 5 um to 1.5 cm and the cell was 3 cm
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Beadle and Tatum... :( last Q for Communication was pretty tough as well.
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Q 10 think it's 10 um because the scale was 5 um to 1.5 cm and the cell was 3 cm
Awesome - cheers! I'll amend the answers and tattoo a ruler to my arm, probably.
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Exam was easier than expected! Communication answers were very forgiving as well :)
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Pretty good
Genetics option was absolutely amazing
I'm so glad!! Sounds like you were well prepared :)
Hopefully you can take a well-deserved break.
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Hey all!
Congratulations on finishing Bio!! Huge!
What did you think of the exam? Let me know below!
I'm working on the suggested answers to the paper now, and I'll update this thread with them soon.
OVERALL THOUGHTS: Coming soon!
MCQs:
1. C (homeostasis)
2. D (nervous)
3. D (frank macfarlane burnet)
4. A (they fight infection)
5. B (comparative anatomy)
6. C (phagocytosis)
7. A (urea)
8. C (pH decreases, acidity increases)
9. B (experiment = 5mL starch + 1mL amylase, control = 5mL starch)
10. B (10µm)
11. D (B cells form clones, T cells do not)
12. B (Tt x tt)
13. A (DNA -> DNA keeps the same sequence. RNA not mentioned. A tricky one!)
14. C (fungi have cell walls, protozoans are unicellular and do not)
15. D (codominance)
16. B (osmosis is a passive process of water moving from high to low concentrations)
17. A (Rosalind Franklin discovered DNA’s double helix shape)
18. C (accuracy = proximity of findings to theoretical findings)
19. A (44 chromosomes/2 + 62 chromosomes/2 = 53 overall. Tricky and IMO not in the syllabus)
20. D (the concentration of the substrate is decreasing)
SAQ: Coming soon!
I believe that 13. Is wrong. It asked for DNA replication and the new strand made..... you eliminated the two with U as this is RNA..... however the new strand would have to align with the original making it the opposite of the original. (Memory isn't great but I think that may have been D)
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What question was 12?
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I believe that 13. Is wrong. It asked for DNA replication and the new strand made..... you eliminated the two with U as this is RNA..... however the new strand would have to align with the original making it the opposite of the original. (Memory isn't great but I think that may have been D)
Yep my answer was D too. First 3 bases were ‘TCC’
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Does anyone remember what the question was for #13 ? Sorry I forgot everything the moment I walked out of school haha
Question 13 was the "A section of DNA has the following nucleotide sequenceL AGG TCT CAG ATC... what is the nucleotide sequence of the newly-made strand following DNA replication?"
What question was 12?
Question 12 is "What is the probability of producing a tall pea plant when heterozygous tall pea plant is crossed with a homozygous short pea plant?"
(Didn't study bio - can't believe how long and sciencey these words are)
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Yep my answer was D too. First 3 bases were ‘TCC’
Yep that was the one
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For question 11 what were the other options again?
Thanks
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Hey all!
Congratulations on finishing Bio!! Huge!
What did you think of the exam? Let me know below!
I'm working on the suggested answers to the paper now, and I'll update this thread with them soon.
OVERALL THOUGHTS: Coming soon!
MCQs:
1. C (homeostasis)
2. D (nervous)
3. D (frank macfarlane burnet)
4. A (they fight infection)
5. B (comparative anatomy)
6. C (phagocytosis)
7. A (urea)
8. C (pH decreases, acidity increases)
9. B (experiment = 5mL starch + 1mL amylase, control = 5mL starch)
10. B (10µm)
11. D (B cells form clones, T cells do not)
12. B (Tt x tt)
13. A (DNA -> DNA keeps the same sequence. RNA not mentioned. A tricky one!)
14. C (fungi have cell walls, protozoans are unicellular and do not)
15. D (codominance)
16. B (osmosis is a passive process of water moving from high to low concentrations)
17. A (Rosalind Franklin discovered DNA’s double helix shape)
18. C (accuracy = proximity of findings to theoretical findings)
19. A (44 chromosomes/2 + 62 chromosomes/2 = 53 overall. Tricky and IMO not in the syllabus)
20. D (the concentration of the substrate is decreasing)
SAQ: Coming soon!
For question 18, was C the one about the scientific literature ?
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For question 18, was C the one about the scientific literature ?
yep :)
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yep :)
Thank you! OMG Last minute, I changed my answer to that hahah
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How many marks do you think I would lose if I spoke about a non infectious disease for the infectious question on treatment and prevention ?😬
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It wasn't on infectious only
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Yeah it didnt state infectious so it could of been either one.
And what was the inheritance of the pedigree, got so confused :(
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The question just said ‘named disease’ so it doesn’t have to be infectious. I did melanoma and the use of public health programs like ‘Slip slop slap’ over expensive treatments
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Yeah it didnt state infectious so it could of been either one.
And what was the inheritance of the pedigree, got so confused :(
Sex-linked recessive if I remember right? The sons in the second gen couldn't have had the characteristic if it was autosomal, since one of the parents "had no recessive allele"
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Overall, I thought the exam was quite easy compared to the past papers. Multiple choice was pretty straight-forward with a couple of trick questions (the complementary base sequence!) I was surprised at the lack of short-answer questions about the practical experiments we performed in class, vaccination programs, anything about the kidney, and anything to do with Mendel, Morgan, Boveri and Sutton. The last short-answer question about Beadle and Tatum + transgenic species was quite WHOA. It took a while for me to formulate an outline for an answer since I never imagined that both of those biology concepts would ever cross paths, but I focused alot on gene expression. My option topic was Genetics, and I thought the questions were easier than past papers. I read through a bunch this morning and the one in the exam was more simpler + straightforward to answer.
What did you guys write for the genotype of the two chromosomes in the short-answer section before crossing over happened? I feel like I stuffed that one up majorly ):
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Yeah it didnt state infectious so it could of been either one.
And what was the inheritance of the pedigree, got so confused :(
I got recessive, sex linked characteristic on the X chromosome
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Sex-linked recessive if I remember right? The sons in the second gen couldn't have had the characteristic if it was autosomal, since one of the parents "had no recessive allele"
Yeah I wrote sex-linked recessive too. If it was autosomal, all the offspring would not have the trait.
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Thank you! OMG Last minute, I changed my answer to that hahah
That, my friend, is a very good feeling
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For the Beadle and Tatum, did you guys talk about how knowledge of how certain genes produce certain polypeptides ( and hence proteins) has allowed transgenic species because we can take out specific genes to allow specific proteins to form in the organism?
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For the Beadle and Tatum, did you guys talk about how knowledge of how certain genes produce certain polypeptides ( and hence proteins) has allowed transgenic species because we can take out specific genes to allow specific proteins to form in the organism?
That's the approach I took as well!
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That, my friend, is a very good feeling
The wave of relief HAHA ;D ;D
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For the Beadle and Tatum, did you guys talk about how knowledge of how certain genes produce certain polypeptides ( and hence proteins) has allowed transgenic species because we can take out specific genes to allow specific proteins to form in the organism?
Yes! I described their findings + explained that + explained process to make Bt cotton and linked parts of it back to finding + explained a bit about how other scientists also contributed to ability for transgenesis
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For the Beadle and Tatum, did you guys talk about how knowledge of how certain genes produce certain polypeptides ( and hence proteins) has allowed transgenic species because we can take out specific genes to allow specific proteins to form in the organism?
Yess
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For the Beadle and Tatum, did you guys talk about how knowledge of how certain genes produce certain polypeptides ( and hence proteins) has allowed transgenic species because we can take out specific genes to allow specific proteins to form in the organism?
Whoooo I wrote something along the lines of that too! Essentially gene expression (:
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What were the other options for Q11? T-cells do form clones don't they
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What were the other options for Q11? T-cells do form clones don't they
I don't remember but I'm pretty sure memory T are cloned as well as cytotoxic? This is the only one I've gotten wrong according to naomi's results but I'm pretty sure her answer isn't correct.
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Was honestly shocked at how easy the MC was, probably easier than any past paper I did. Loved the 8 marker tbh but the 7 marker on hearing technologies was a pain in communication. Never revised the transport mechanisms in phloem or looked over the transverse diagrams of xylem/phloem which I'm annoyed at myself about but other than that it was a pretty easy exam (for biology). What did people put for the question that asked for the genotype of the chromosomes? Wasn't too sure what to put but I just wrote "heterozygous" and i'm not too confident about that haha.
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I don't remember but I'm pretty sure memory T are cloned as well as cytotoxic? This is the only one I've gotten wrong according to naomi's results but I'm pretty sure her answer isn't correct.
yeah, I thought T cells are cloned too... I picked the option with them both having markers to detect antigens or something like that (i forgot how it was phrased),
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11 should be the option about both T and B having specific recognition thingos or whatever
Helper T-cells have surface receptor protein specific to antigens and B-cells have MHCII glycoprotein molecules
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Was honestly shocked at how easy the MC was, probably easier than any past paper I did. Loved the 8 marker tbh but the 7 marker on hearing technologies was a pain in communication. Never revised the transport mechanisms in phloem or looked over the transverse diagrams of xylem/phloem which I'm annoyed at myself about but other than that it was a pretty easy exam (for biology). What did people put for the question that asked for the genotype of the chromosomes? Wasn't too sure what to put but I just wrote "heterozygous" and i'm not too confident about that haha.
I'm not sure if my answer for genotype was correct, but I wrote "ABG, abg"
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Prepare for a high as fuck cut off this year
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Was honestly shocked at how easy the MC was, probably easier than any past paper I did. Loved the 8 marker tbh but the 7 marker on hearing technologies was a pain in communication. Never revised the transport mechanisms in phloem or looked over the transverse diagrams of xylem/phloem which I'm annoyed at myself about but other than that it was a pretty easy exam (for biology). What did people put for the question that asked for the genotype of the chromosomes? Wasn't too sure what to put but I just wrote "heterozygous" and i'm not too confident about that haha.
Genotype is Aa Bb Gg
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But the cell was 3cm across and 1cm = 5um according to their scale. Or am I just an idiot who can't use a ruler ?
And also don't t cells replicate - burnets clonal selection theory and all?
Thanks for posting all of this though!
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But the cell was 3cm across and 1cm = 5um according to their scale. Or am I just an idiot who can't use a ruler ?
And also don't t cells replicate - burnets clonal selection theory and all?
Thanks for posting all of this though!
Ahahaha! Don't worry you aren't the only one :(
I'm thinking the same thing, I felt like it was C
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But the cell was 3cm across and 1cm = 5um according to their scale. Or am I just an idiot who can't use a ruler ?
And also don't t cells replicate - burnets clonal selection theory and all?
Thanks for posting all of this though!
The scale was 1.5cm = 5um, so 3cm = 10um. Must have misread, unlucky :(
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But the cell was 3cm across and 1cm = 5um according to their scale. Or am I just an idiot who can't use a ruler ?
And also don't t cells replicate - burnets clonal selection theory and all?
Thanks for posting all of this though!
Yeah I thought T cells get cloned too? Hmm.
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The question just said ‘named disease’ so it doesn’t have to be infectious. I did melanoma and the use of public health programs like ‘Slip slop slap’ over expensive treatments
That's so good 😊 !!!
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it was a pretty good exam only annoying question was the beadle and tatum 8 marker
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Yeah I thought T cells get cloned too? Hmm.
yes i think they do! I just checked biology in focus and it said they do
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Rip just realised i drew a longitudinal section of the plants :( Why the hell did they want as to draw a transverse if its basically the same thing
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Naomi has finished the short answer questions! Head back to page one of this thread to check them out!
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A
For the Beadle and Tatum, did you guys talk about how knowledge of how certain genes produce certain polypeptides ( and hence proteins) has allowed transgenic species because we can take out specific genes to allow specific proteins to form in the organism?
Absolutely!! Check my skeleton of a sample answer above :)
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Rip just realised i drew a longitudinal section of the plants :( Why the hell did they want as to draw a transverse if its basically the same thing
So far I've seen a lot of people tricked by it, and probably WAS the reason they wanted transerve, to trick people ;)
Also, my diagram was pretty wonky, that shouldn't have an effect on the mark right?
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I honestly thought today was the fairest and most straightforward HSC exam l have ever come across. Great timing and the communication topic l thought was excellent. I honestly thought T-Cells cloned too but l am more than happy to say l am wrong. Now that genotype question came up in 2002 (see below) and going from that I assume the answer will be Aa Bb Gg (which l am pissed off at cause l should have known but oh well). The 8 marker l thought was reasonable. But l hell of a lot to talk about. All in all a great exam
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Did anyone else write about malaria for Q29 and talked about the possible evolution of plasmodium that is resistant to anti-malarial drugs?
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What do you guys think the cut off for a band 6 will be?
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Did anyone else write about malaria for Q29 and talked about the possible evolution of plasmodium that is resistant to anti-malarial drugs?
Yup! I wrote about Malaria as well like how the Plasmodium became resistant to drugs like equinine..
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With the franklin multiple choice, could the answer of been sugar phosphate backbone as she did discover this as well? I thought it was mainly Watson and crick for double helix structure, like I know she contributed but it wasn't the main feature she came up with?
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Have amended by answer to question 11 - thanks for the feedback guys!
Both B and T cells can form clones by clonal proliferation. HOWEVER; whilst B-cells can recognise specific antigens, T-cells only recognise them in the context of MHC - a special protein (a little beyond the scope of the syllabus)... So based on the wording of the question, I don't think C) is technically correct either. I think it is just the *most* correct.
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Thanks so much!! Just for question 20 I couldn't really pick between A and D and ended up going with A - can someone please explain why it would be D because I don't really understand?
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Disappointed that I got 18/20 for mc -- changed my answers for both of them in the last minute. sad
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Have amended by answer to question 11 - thanks for the feedback guys!
Both B and T cells can form clones by clonal proliferation. HOWEVER; whilst B-cells can recognise specific antigens, T-cells only recognise them in the context of MHC - a special protein (a little beyond the scope of the syllabus)... So based on the wording of the question, I don't think C) is technically correct either. I think it is just the *most* correct.
Would question 13 possibly be D, as with the DNA replication it was the new strand being formed and so would have the complimentary bases of the original DNA sequence?
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Thanks so much!! Just for question 20 I couldn't really pick between A and D and ended up going with A - can someone please explain why it would be D because I don't really understand?
Sure!
A = the rate of enzyme activity is decreasing
D = the substrate concentration is decreasing
D makes sense, as the substrate is being transformed into products by the reaction, which are then removed.
A doesn't make sense, as the question stated specifically that the experiment was *valid* - meaning that the variables were properly controlled to test the effect of substrate concentration. For the rate of enzyme activity to decrease, conditions would have to change, meaning that the experiment would not be valid.
Hope that answers your question!
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Would anyone Pls do suggested answers for communication
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For treatment vs. prevention, could you talk about bacterial strains being resistant to antibiotics? Thus, treatment only works well in a shorter timespan, as opposed to prevention.
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Thank you times a million to Naomi for providing her insight!! Naomi's schedule is stupidly busy (did you know she studies Med?) and she made time to go through these, even though it took a little longer than we anticipated!
Feel free to keep chatting everyone!
Disappointed that I got 18/20 for mc -- changed my answers for both of them in the last minute. sad
I know that frustration, but that is still an incredible MC mark!
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What do you guys think the cut off for a band 6 will be?
Honestly, I can see it potentially being around 84-86 this year, usually it's around 80/81
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Disappointed that I got 18/20 for mc -- changed my answers for both of them in the last minute. sad
Feeling your pain as well.
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Hey did anyone else put sugar phosphate backbone for franklin?
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Does anyone know what a raw of mark 88-89 could possibly align to? Thanks :)
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Does anyone know what a raw of mark 88-89 could possibly align to? Thanks :)
Check hsc raw marks database. I am going to assume about a 93 or a 94. It really just depends on the band 6 cut off this year
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Sure!
A = the rate of enzyme activity is decreasing
D = the substrate concentration is decreasing
D makes sense, as the substrate is being transformed into products by the reaction, which are then removed.
A doesn't make sense, as the question stated specifically that the experiment was *valid* - meaning that the variables were properly controlled to test the effect of substrate concentration. For the rate of enzyme activity to decrease, conditions would have to change, meaning that the experiment would not be valid.
Hope that answers your question!
I thought this differently tho. It never states it was an experiment to test the effect of concentration. Also because that graph shows product produced in each 10min period, the decrease in products means that the rate of reaction is not constant, otherwise the amount of product every 10min produced should stay the same right?
Plez prove me wrong tho, I do think A is unlikely but it made sense to me :(
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13 they might accept 2 answers it was such a broad question
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I thought this differently tho. It never states it was an experiment to test the effect of concentration. Also because that graph shows product produced in each 10min period, the decrease in products means that the rate of reaction is not constant, otherwise the amount of product every 10min produced should stay the same right?
Plez prove me wrong tho, I do think A is unlikely but it made sense to me :(
This is what I was thinking in the exam! They both make sense to me (Thanks for the explanation for why it would be D naomi!) if you think about the experiment in different ways as I don't think they specified what exactly they were testing? I don't remember the exact question though so not sure
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With the genotype question that was a multiple choice from 2001 and the answer was ABG, abG, ABg, and abg so why is the answer different this time?
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With the genotype question that was a multiple choice from 2001 and the answer was ABG, abG, ABg, and abg so why is the answer different this time?
I did the same thing, confused as to why it's different as well.
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With the genotype question that was a multiple choice from 2001 and the answer was ABG, abG, ABg, and abg so why is the answer different this time?
I honestly can't believe it, if that is the right answer l am going to be so happy. Obviously, they asked for before the crossing over occurs so l would assume, ABG ABG, abg and abg as the answers
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I honestly can't believe it, if that is the right answer l am going to be so happy. Obviously, they asked for before the crossing over occurs so l would assume, ABG ABG, abg and abg as the answers
do you reckon ABG, abg would be fine as well if the answer follows the same as 2001? since the chromosomes duplicate for meiosis but original genotype would be halved
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Shouldn't 9 be 5ml of starch and 1 ml of water for control so that the volume is kept the same?
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I honestly can't believe it, if that is the right answer l am going to be so happy. Obviously, they asked for before the crossing over occurs so l would assume, ABG ABG, abg and abg as the answers
Yeah looking at this https://gyazo.com/e61a5586c44f62f92b9296400b20d9f6 it should be right you'd think?
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Beadle and Tatum... :( last Q for Communication was pretty tough as well.
I feel ya :(
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For the genotype I wrote Aa and not all the possibilities as it was only one mark. Will I get 0?
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Shouldn't 9 be 5ml of starch and 1 ml of water for control so that the volume is kept the same?
No, now you are not controlling the variables. If using water and starch as the control then for the experiment you would need to have water, starch and amalayse. But because it is only asking for amalayse and starch. And seeing as there was no option for water amalayse and starch then the only possible answer is just starch for the control and amalayse and starch for the experiment
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Yeah looking at this https://gyazo.com/e61a5586c44f62f92b9296400b20d9f6 it should be right you'd think?
One would hope, l guess we will only know when the NESA answers come out
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Exam was way too easy in my opinion. I'm not sure exactly how NESA is going to be able to differentiate people as easily.
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How did people find communication? Any suggested answers?
Hey I personally found it quite ‘forgiving’ compared to previous years :) although I got confused on the rhodopsin and rods question.. for part (i) I just said that rhodopsin breaks down to retinal and opsin , and for part (ii) in comparing rods and cones, I didn’t think that the rods’ peripheral acuity & ability to distinguish between light & dark shades was enough for a 4-5 marker so I repeated what I said about rhodosopin. Hopefully won’t lose marks for writing too much haha. How’d you find it? :)
Moderator edit: updated username in quote as per request —Calebark
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If possible can someone please post a copy of the exam, or at least the multiple choice section? I can't remember all the options for each question haha so I don't know what I chose
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How did people find communication? Any suggested answers?
- Rhodopsin are in rods right? LOL
- The lens changes curvature when focusing on a near object as the ciliary body muscles contract, and the suspensory ligaments are no longer taught, thus creating a thicker and rounder lens. When the eye is focusing on an image in the distance, the ciliary body muscles are relaxed and taught, and the lens is now flat and thin.
- For the threshold potential question, signal 1 couldnt result in a transmission of stimulation as it did not generate the threshold action potential greater than -70mV. For part 2, I talked about depolarisation, repolarisation, hyperpolarisation and the resting membrane potential and drew the chemical membrane cause why not!
- For the last 7 marker question I defined what soundwaves were, explained how we hear through the different structures and their function (as well as their energy change and how it is transmitted to the auditory cortex/temporal lobe), then reiterated that from our understanding of the human ear, if one structure was not functioning properly, our hearing would be compromised. Then insert cochlear implant and the hearing aid (function, where it’s worn, energy changes and the type of people to use these devices) and concluded it! I’m not sure if I properly answered the question, but I just regurgitated anything about the ear and the development of technology to assist people with hearing loss.
How was it for you?
Moderator edit: updated username in quote as per request —Calebark
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If possible can someone please post a copy of the exam, or at least the multiple choice section? I can't remember all the options for each question haha so I don't know what I chose
No one has a copy of the exam yet but NESA has been quite quick in uploading them this year so it should be up on their website in a couple of days :)
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If possible can someone please post a copy of the exam, or at least the multiple choice section? I can't remember all the options for each question haha so I don't know what I chose
Q1 was about which process maintains an internal stable environment?
Q2 was about which system could detect and counteract changes in the external environment?
Q3 was about which scientist gave a better understanding (can't remember exact wording) about the immune response?
Q4 was about the role of the lymphocytes.
Q5 had an image and made us pick which evolutionary evidence was applied
Q6 was about which process engulfs the antigen.
Q7 was about the waste product of renal dialysis
Q8 was about how carbon dioxide changes the pH and acidity
Q9 had a fair experiment, and made us pick the controlled and experiment.
Q10 had a picture of a cell with a scale; it made us work out the exact measurement of the cell.
Q11 had a table about B and T lymphocytes, and we had to conclude which was correct based on the information we know.
Q12 was about the percentage of tall offsprings based on the genotypes of the parents.
Q13 had a sequence of amino acids. After DNA replication, what is the sequence of amino acids on the "newly made strand" of DNA?
Q14 we had to distinguish which row was correct between protozoans and fungi.
Q16 had a table (diffusion, osmosis, active transport, or passive transport)
Q17 was about the discoveries of the DNA made after Rosalind Franklin's work?
Q19 had a 44 chromosome zebronkey and a 62 chromosome other animal, and we had to work out the number of chromosomes in the offspring
Q20 had a trend after every 10 minutes, what could we conclude from the graph?
These are from my memory, not sure if I'm supposed to post it
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- Rhodopsin are in rods right? LOL
- The lens changes curvature when focusing on a near object as the ciliary body muscles contract, and the suspensory ligaments are no longer taught, thus creating a thicker and rounder lens. When the eye is focusing on an image in the distance, the ciliary body muscles are relaxed and taught, and the lens is now flat and thin.
- For the threshold potential question, signal 1 couldnt result in a transmission of stimulation as it did not generate the threshold action potential greater than -70mV. For part 2, I talked about depolarisation, repolarisation, hyperpolarisation and the resting membrane potential and drew the chemical membrane cause why not!
- For the last 7 marker question I defined what soundwaves were, explained how we hear through the different structures and their function (as well as their energy change and how it is transmitted to the auditory cortex/temporal lobe), then reiterated that from our understanding of the human ear, if one structure was not functioning properly, our hearing would be compromised. Then insert cochlear implant and the hearing aid (function, where it’s worn, energy changes and the type of people to use these devices) and concluded it! I’m not sure if I properly answered the question, but I just regurgitated anything about the ear and the development of technology to assist people with hearing loss.
How was it for you?
Hi for the 7 marker did you talk about the microphone and amplifier and basically all the individual parts in cochlear implant and hearing aid? :)
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Hi for the 7 marker did you talk about the microphone and amplifier and basically all the individual parts in cochlear implant and hearing aid? :)
I mainly talked about it with the hearing aid. With the cochlear implant I talked a bit about it but I was mainly talking about the organ of corti and the hair cells
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- Rhodopsin are in rods right? LOL
- The lens changes curvature when focusing on a near object as the ciliary body muscles contract, and the suspensory ligaments are no longer taught, thus creating a thicker and rounder lens. When the eye is focusing on an image in the distance, the ciliary body muscles are relaxed and taught, and the lens is now flat and thin.
- For the threshold potential question, signal 1 couldnt result in a transmission of stimulation as it did not generate the threshold action potential greater than -70mV. For part 2, I talked about depolarisation, repolarisation, hyperpolarisation and the resting membrane potential and drew the chemical membrane cause why not!
- For the last 7 marker question I defined what soundwaves were, explained how we hear through the different structures and their function (as well as their energy change and how it is transmitted to the auditory cortex/temporal lobe), then reiterated that from our understanding of the human ear, if one structure was not functioning properly, our hearing would be compromised. Then insert cochlear implant and the hearing aid (function, where it’s worn, energy changes and the type of people to use these devices) and concluded it! I’m not sure if I properly answered the question, but I just regurgitated anything about the ear and the development of technology to assist people with hearing loss.
How was it for you?
Should be taught not taught
BTW to the person asking if you can lose marks for writing too much, no you can't unless you wrote wrong content. You can only lose marks for writing too little.
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Q1 was about which process maintains an internal stable environment?
Q2 was about which system could detect and counteract changes in the external environment?
Q3 was about which scientist gave a better understanding (can't remember exact wording) about the immune response?
Q4 was about the role of the lymphocytes.
Q5 had an image and made us pick which evolutionary evidence was applied
Q6 was about which process engulfs the antigen.
Q7 was about the waste product of renal dialysis
Q8 was about how carbon dioxide changes the pH and acidity
Q9 had a fair experiment, and made us pick the controlled and experiment.
Q10 had a picture of a cell with a scale; it made us work out the exact measurement of the cell.
Q11 had a table about B and T lymphocytes, and we had to conclude which was correct based on the information we know.
Q12 was about the percentage of tall offsprings based on the genotypes of the parents.
Q13 had a sequence of amino acids. After DNA replication, what is the sequence of amino acids on the "newly made strand" of DNA?
Q14 we had to distinguish which row was correct between protozoans and fungi.
Q16 had a table (diffusion, osmosis, active transport, or passive transport)
Q17 was about the discoveries of the DNA made after Rosalind Franklin's work?
Q19 had a 44 chromosome zebronkey and a 62 chromosome other animal, and we had to work out the number of chromosomes in the offspring
Q20 had a trend after every 10 minutes, what could we conclude from the graph?
These are from my memory, not sure if I'm supposed to post it
Thank you! Also with the 2 mark question about drawing a diagram of xylem and phloem, is it 1 mark for drawing it, and another for correctly labelling it?
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Thank you! Also with the 2 mark question about drawing a diagram of xylem and phloem, is it 1 mark for drawing it, and another for correctly labelling it?
I would've thought a mark for the transverse of each.
So, one mark for transverse section of a xylem and one mark for transverse of phloem.
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I would've thought a mark for the transverse of each.
So, one mark for transverse section of a xylem and one mark for transverse of phloem.
Both are just circles so I doubt they'd give a mark for each
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Hi I was just wondering how Q15 of MC is codominace?
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Ok so i completely messed up for the artery and vein question and put them the wrong way around. Is there any hope at getting at least one or two marks or did i just lose the easiest 5 marks of my life?? :'(
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Hi I was just wondering how Q15 of MC is codominace?
Write genotypes as AA and BB then offspring is all AB hence codominance
If it wasn't then say AA and aa so all offspring are same phenotype as the parent AA hence it is wrong
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(http://uploads.tapatalk-cdn.com/20171025/113f5dfee5a297205f6454ef7ffd88e0.jpg)
They’ve recycled the question lol.
I wrote
Before - ABG, ABG, abg , abg
After - ABG, abG, ABg, abg
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Hey for the question with the substrate (question 20 in multiple choice), how can it be A or D? cause basically isnt that the same thing? decreasing the concentration of the substrate decreases the rate of reaction? Also, for the question with the image of the chromosomes and crossing over, I only wrote one of the possible 4. Reckon theyll take the mark away? What do u reckon will be band 6 o.o ??? ???
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Definitely felt like Q19 was testing your knowledge on whether you could apply what Mendel, Sutton and Boveri discovered!
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Hey for the question with the substrate (question 20 in multiple choice), how can it be A or D? cause basically isnt that the same thing? decreasing the concentration of the substrate decreases the rate of reaction? Also, for the question with the image of the chromosomes and crossing over, I only wrote one of the possible 4. Reckon theyll take the mark away? What do u reckon will be band 6 o.o ??? ???
Mm maybeee?? Cause it was plural, “genotypeS”
Maybe around like 95+? Considering it was fair and most likely, the state must’ve done well too
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Mm maybeee?? Cause it was plural, “genotypeS”
Maybe around like 95+? Considering it was fair and most likely, the state must’ve done well too
Lol 95 for a band 6?, its gonna be more like a 83-84
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Hey for the question with the substrate (question 20 in multiple choice), how can it be A or D? cause basically isnt that the same thing? decreasing the concentration of the substrate decreases the rate of reaction? Also, for the question with the image of the chromosomes and crossing over, I only wrote one of the possible 4. Reckon theyll take the mark away? What do u reckon will be band 6 o.o ??? ???
I think the reason why it’s D for Q20 cause an enzyme-substrate reaction causes the substrate to break down, thus decreasing concentration of substrate. This was given as a hint for the first question of Q21 if you observed the diagram carefully and made links!
I got that question wrong too :/ realised when I got out of the exam that I could’ve used the diagram
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Lol 95 for a band 6?, its gonna be more like a 83-84
Most likely lol
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Hey hey heyyyyy XD thanks for the reply (: idk how this system works :/ so when they say for example band 6 cut off is 95, do they mean raw mark of 95 0.0 Im soooo lossstttt 0.0 .
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No worries :)
I think it’s based off raw first. I’m not entirely sure, but my thinking is that , if an exam was hard and let’s say the highest mark of that was 85(top 0.15% of the scores). This means the data would be positively skew, which results in the scores to shift upwards to be more normally distributed (bell shape)... so those who got 85 will probably get like 90+ now.
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Guys for the crossing over question, is it the G's that cross over? That's what I gathered from that 2001 MC. How can it be A and B because then you will get multiple combinations as genes cross over independently of all other genes i.e. a allele won't necessarily cross over with b allele. I got ABG ABg abG abg? Is that the same as ABG abG ABg abg?
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Thoughts for raw band 6 cut off?
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For question 19 in multiple choice, wasn't 53 the total haploid number, making the total diploid number of the chromosomes 106?
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For question 19 in multiple choice, wasn't 53 the total haploid number, making the total diploid number of the chromosomes 106?
Hi!
One parent had 44 chromosomes, the other had 62. Half of the genetic information from parent 1 (22) is added to half of the genetic information from parent 2 (31) which makes the diploid number 53. :)
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Guys for the crossing over question, is it the G's that cross over? That's what I gathered from that 2001 MC. How can it be A and B because then you will get multiple combinations as genes cross over independently of all other genes i.e. a allele won't necessarily cross over with b allele. I got ABG ABg abG abg? Is that the same as ABG abG ABg abg?
The crossing over point indicates that the alleles above it, only cross . The G/g alleles and ABG of first set of homologous chromosome (most left one) and abg of Second set of homologous chromosomes (most Right) don’t have it , therefore they do not cross.
Thus, only producing ABG**, (ab)G, (AB)g, abg** once crossed over.
* brackets () - indicate the alleles that have exchanged/crossed over
** - these stay the same due to no available crossing over point.
Hope that makes sense :)
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For question 19 in multiple choice, wasn't 53 the total haploid number, making the total diploid number of the chromosomes 106?
Hey there! :)
What Jess has said is correct!!
I immediately thought about Mendel, Sutton and Boveri’s discoveries and what understandings they’ve given us about inheritance, then applied it to the question.
This one was definitely a high order question!
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(http://uploads.tapatalk-cdn.com/20171025/113f5dfee5a297205f6454ef7ffd88e0.jpg)
They’ve recycled the question lol.
I wrote
Before - ABG, ABG, abg , abg
After - ABG, abG, ABg, abg
Nah before is not that because those are the replicated chromosomes (92 chromosomes) when the genotype should be 46
Also rip we didn't learn that you should cross above the line
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Since my estimated mark is 74 (Im so disappointed, lost so much marks for misreading questions), does it get scaled at all (since the exam was quite easy)? Would this be an early band 4? Have I failed biology??
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Nah before is not that because those are the replicated chromosomes (92 chromosomes) when the genotype should be 46
Also rip we didn't learn that you should cross above the line
Sameee I didn’t too! :((
But I was lucky to have come across this question the day before and figured it out my self !
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Since my estimated mark is 74 (Im so disappointed, lost so much marks for misreading questions), does it get scaled at all (since the exam was quite easy)? Would this be an early band 4? Have I failed biology??
Same, my short answers were atrocious! But my mcq and options were okay.
No, I don’t think you will fail biology! I’m sure you did fineee, we really don’t know whether we did well or not. :)
And remember , there are many factors that count to moderating and scaling. Not only how well the state did
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Sameee I didn’t too! :((
But I was lucky to have come across this question the day before and figured it out my self !
Oh rip so far I've lost 2 on MCQ and 2 on short answer hopefully that's it because aligning won't be that high this year
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Oh rip so far I've lost 2 on MCQ and 2 on short answer hopefully that's it because aligning won't be that high this year
Same got 18 :( for mcq
Probably lost 5-8 marks for short answers
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Is there options answer?
Also isnt the mcq for the dna strand D? I dont think it's A
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Is there options answer?
Also isnt the mcq for the dna strand D? I dont think it's A
It says D
It could be either the wording was crap
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hey do you guys know what q28 was? its not on the first page and i'm panicking :'(
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nvm! i just realised it was the pedigree question :)
what do you think an ~80 ish mark would scale to in this exam? the exam wasn't too bad but i think i missed out on quite a bit of small marks
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I forgot to draw in a punnet square in my explanation for the characteristic of inheritance question (pretty sure this was q 28), am I going to lose a lot of marks?
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I forgot to draw in a punnet square in my explanation for the characteristic of inheritance question (pretty sure this was q 28), am I going to lose a lot of marks?
I don't remember it saying "show your working'... So, if you explained why it was sex-linked recessive by referring to the genotypes of certain individuals and all. You'll be fine! :)
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I don't remember it saying "show your working'... So, if you explained why it was sex-linked recessive by referring to the genotypes of certain individuals and all. You'll be fine! :)
:') Thanks that makes me feel better.
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Can someone show me the answers for Q32 the communication section?
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What do you think will be the cut off for a Band 5 and Band 6?
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What do you think will be the cut off for a Band 5 and Band 6?
B6 maybe 85
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B6 maybe 85
I feel like it would be high 80s to low 90s
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I feel like it would be high 80s to low 90s
Marks can't align down so I doubt it'd be in the 90s
Plus it wasn't THAT easy because the crossing over one was hard, 8 marker may have tricked people, and a couple tricky MC
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NESA have released the paper.
http://educationstandards.nsw.edu.au/wps/wcm/connect/fc23024b-f91e-468c-90b5-8d522b8d2dbf/2017-hsc-biology.pdf?MOD=AJPERES&CACHEID=ROOTWORKSPACE-fc23024b-f91e-468c-90b5-8d522b8d2dbf-lZqLe2b
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so..... Answers came out and they said 9 was A..... can someone explain why please?
Also said 13 was D, so rip :P