VCE Biology Exam - 01/11/19 - Discussion/Questions/Solutions

[ssillyssnakes]

what was the answer to the brain size mc question?? i was tossing up between homo sapiens and homo floresiensis, but ended up choosing the latter. now i regret my choice lol.

I'd be shocked if it were homo sapiens, because florensis was was later than all the other small brain hominoids whilst the difference between Neanderthals and sapiens is like.... small

[Majestic Dragon]

"I think that question was talking about post transcriptions modification, so like most of the 300 monomers were introns and spliced out"

yessirrr makes sense

[3086]

Also what about why does mutation in bmp4 affect phenotypes? 3 marks

[3086]

"I think that question was talking about post transcriptions modification, so like most of the 300 monomers were introns and spliced out"

yessirrr makes sense

yesssss I wrote that but do I lose a mark for saying not saying it's spliced out

[Genshai]

I'd be shocked if it were homo sapiens, because florensis was was later than all the other small brain hominoids whilst the difference between Neanderthals and sapiens is like.... small

ahh i hope so !! that was my reasoning too, but when i came out of the exam, everyone said they had h sapien and i started doubting myself T_T

[Kingzone]

What was answer to whether the Denisovans and Neanderthals were one species ?

I said that without DNA analysis, you could not determine whether they were one species due to the fossil record being incomplete (only one finger bone present)

Not sure though.

I'd be shocked if it were homo sapiens, because florensis was was later than all the other small brain hominoids whilst the difference between Neanderthals and sapiens is like.... small

I too said H. florensis because the key wording was "Which one did not follow the usual trend of hominid evolution?
Florensis came later after afarensis and africans but it had a smaller cranium capacity to both of them, therefore not following the trend.

Oh damn that's actually smart. I just said they should repeat it more lol

I'm not exactly sure whether my answer is viable, but I mentioned that they could extend the range of temperatures tested from 5-> 35 to 5-> 90 degrees as the experiment was only limited to 35*C (note that at higher temperatures the enzyme denatures at the active site thus not able to conduct the reaction)

I wrote something about the constant region of antibodies being similar and the differences in antigen binding site being very minute and small... probably wrong though.

Funnily enough, found it much harder than 2017 and 2018. I made some silly mistakes...

I said something similar too + I mentioned that the structure of the antibody has 2 light chains and 2 heavy chains + 2 antigen binding sites.

****
I didn't know how to justify why scientists used Nuclear DNA instead of mitochondrial DNA. I bsed it and said that "Mitochondrial DNA is passed down maternally and is highly conserved whereas nuclear DNA contains DNA from both parents which allows scientists to notice evolutionary links in similarities of DNA between Denisovans and Neanderthalensis." (Yeah def not right)

Secondly, I was kind of confused about the errors. I think somewhere between student A, B and C I said that they could have incorrectly measured the amount of enzyme put in the solutions causing an increase in rate of reaction therefore decreasing time needed to neutralise the solution./ incorrectly measuring temperature of water bath leading to higher than expected temperature in water bath therefore increasing rate of reaction leading to overall decreased time required to neutralise the solution.

[PhoenixxFire]

I got a copy but I'm missing a few questions but will hopefully get them at some point. For now will post the answers as I write them, once they're all done I'll make a pdf with them all so it's less messy. For now I'm just going to chuck up the answers for the multiple choice, but I'll try and include a bit of a summary for the short answer questions. Will write a proper description when I make the pdf so that those of you who don't have copies of the exam can figure out what the question was.

Feel free to question any of this, it's entirely possible that I'll make mistakes.

1. C
2. B
3. B
4. D
5. A
6. D
7. D
8. D
9. A
10. D
11. A
12. B
13. B
14. A
15. C
16. D
17. C
18. B
19. D
20. N/A

[BitcoinEagle]

Hey Pheonixxfire, could you upload photos of the exam?

[Majestic Dragon]

 
Yep,couldn't conduct comparative anatomy of a finger and adult tooth ,insufficient information hence without dna analysis the difference between the two species cannot be determined

[PhoenixxFire]

Hey Pheonixxfire, could you upload photos of the exam?

It's still under VCAA copyright so we can't post it here until after they put it up on their own website.

[BitcoinEagle]

It's still under VCAA copyright so we can't post it here until after they put it up on their own website.

Ok sure, what was the question that had no right answer tho? And why is 20 NA?

[PhoenixxFire]

Ok sure, what was the question that had no right answer tho? And why is 20 NA?

The question about photosynthetic rate at varying light intensities. Question 20 is on the page of the exam that I'm missing.

[Sconey]

The question about photosynthetic rate at varying light intensities. Question 20 is on the page of the exam that I'm missing.

I think you might be reading the graph incorrectly. The line plateaus at a photosynthetic rate of 40 (on the y-axis); thus before the rate of 40 is reached, light intensity is the limiting factor. 

[PhoenixxFire]

I think you might be reading the graph incorrectly. The line plateaus at a photosynthetic rate of 40 (on the y-axis); thus before the rate of 40 is reached, light intensity is the limiting factor. 

Yikes I should really know how to read a graph by now. Yep you're right.

21. N/A
22. N/A
23. N/A
24. C
25. D
26. C
27. C
28. C
29. D
30. B
31. A
32. D
33. D
34. B
35. B
36. A
37. C
38. A
39. C
40. D

[J_Rho]

Also what about why does mutation in bmp4 affect phenotypes? 3 marks

I wrote something about the fact that due to BMP4 being expressed less, CaM had more effect on the size and shape of the beaks. Idk im probably wrong thoo 😂