Biology: Discussion, Questions & Potential Solutions

[jinaede1342]

Question 2
a.   Cell shrinks and loses contact with neighbouring cells, leading to the condensation of chromatin and its' degradation (1m); nuclear membrane degrades while the chromatin clumps into chromatin bodies (1m); the cell breaks into apoptotic bodies containing densely packed organelles (1m). - Blebbing is not an acceptable answer; choose two

Could activated caspases be considered correct here

[PhoenixxFire]

Multiple choice - suggested answers

Hey guys! We've found a copy of the exam so we're going to start uploading suggested answers.
Here's the answers we got for the multiple choice (we were missing one page, which is why some have question marks)

1. B
2. C
3. D
4. B
5. C
6. C
7. D
8. C
9. A
10. A
11. C
12. D
13. B
14. B
15. B
16. B
17. A
18. D
19. C
20. C
21. A
22. C
23. D
24. B
25. A
26. A
27. A
28. D
29. A
30. C
31. B
32. ?
33. ?
34. ?
35. ?
36. ?
37. B
38. C
39. B
40. C

[vox nihili]

Here's question 1.

[yeetlebeetle]

MOD EDIT: the request of copyrighted materials is banned.

It has been our practice in previous years to post exam booklets; however, VCAA has asserted their copyright in multiple spaces such as this in the past years. We agree that it is frustrating, but ultimately copyright does secure an organisation's right to have its intellectual property protected.

[vox nihili]

Question 2

This question dealt with apoptosis.

Potentially a number of potential answers here, including: cleavage of caspases, release of cytochrome c from mitochondria, autodigestion of cellular contents.
Apoptosis facilitates the removal of defective cells and allows for the refinement of normal development.

Would accept other answers here. Any reference to the role of apoptosis in clearing infection or cancer is reasonable.


There may be a mutation in a death receptor molecule that makes it constitutively active/more sensitive to death ligands, thereby seeing the threshold for the activation of apoptosis decrease and more apoptosis occur.

As above, there are many potential answers here. The marks will come from providing a reasonable (at a VCE level) mechanism for the increased likelihood of apoptosis and making a statement about the effect of your described mechanism on seeing more cells die.


EDIT: formatting didn't work—we'll post a complete set of answers later, but this is legible from context.

[vox nihili]

[yeetlebeetle]

MOD EDIT: please see above about obtaining a copy of the exam. Anyone who asks for copyrighted material on this thread from here on in will receive a ban.

[vox nihili]

Question 4

This question dealt with cellular transport processes and the immune system through the prism of Botulinum toxin.

Your diagram should show a plasma membrane with an indentation containing clearly labelled Botox [1] and the sides of the membrane should be labelled correctly [2].
Botox could attach to the active site of the protein and thereby inhibit its function.

Many potential answers for this one. The assessors seem to have expected an answer about the fact that Botox destabilises the quaternary structure of the enzyme, but this is unreasonable for VCE biology. Any bioplausible answer should be acceptable.

The reality is that Botox is an enzyme that cleaves SNARE proteins, which anchor vesicles at the plasma membrane for exocytosis. In this way, Botox prevents the exocytosis of neurotransmitters and therefore blocks nerve transmission. This level of detail is not relevant to VCE.
Botox is a protein and will therefore be recognised as non-self [1]. B-cells will produce antibodies complementary to Botox that block its activity [2]. Each injection of Botox leads to a greater immune response to it, thereby explaining the gradual decline in its potency [3].

The same is also true of many antisera. Don't get bitten by a snake twice!




To be clear, PF is helping with all of these questions too

[vox nihili]

[jinaede1342]

Hi, I would like to thank the moderators for taking the time to provide us with these answers, your work doesn't go unnoticed, and has definitely alleviated stress on my part at the very least. After all the answers have been posted, would it be possible to give us an idea of how hard you believe the exam was now that you have access to a copy, and a rough idea of what the A+ cutoff will be. Thanks! 

[Tadd12345]

didn't they say that the pH indicator turns yellow in the presence of low carbon dioxide and pink in high presence of carbon dioxide. Due to carbon dioxide levels decreasing, the solution will turn from pink to yellow no?

[vox nihili]

Here are the completed answers that PhoenixxFire and I put together tonight.

These are the answers as we see them; however, we'd really welcome any discussion here and will stick around to answer any questions you have.

The answers contain:

-MCQ answers (checked off by Sine, too!)
-MCQ explanation
-SAQ answers and explanation

[Elsa//768]

What does everyone think this year A+ cutoff score is gonna be 
I hope it's gonna be lower than last year's score coz I thought this year's short-answer part was harder... (or maybe it was just me ;-;)

[lacitam]

Here's question 1.

(Image removed from quote.)

How is a vesicle an organelle?

[Erutepa]

For 7b, would it not have been important to specify the founder's effect?

And many thanks to PF and Vox as well as sine (but only a little to sine ) for their fantastic work tonight.