Hi guys!
I just finished marking the 2018 Biology VCAA exam I did and I had a few questions regarding my own answers.
2.c (2 marks)
In some human diseases, malfunctions in programmed cell death result in the death of too many cells.
Explain at a cellular level what may have gone wrong to bring about this excessive cell death.
What I wrote:
There may be an excessive amount of signalling molecules such as death ligands initiating programmed cell death. A certain gene may be expressed at a higher intensity causing the production of a lot of signalling proteins.
Is what I wrote sufficient? I'm not sure if I should add anything else.
As stated in the examiner's report, the question required you to not only state what could have happened, but how that thing would have caused this excessive cell death. You have correctly stated the greater production of death ligands, but you need to give a bit further detail about how this would have caused excessive cell death.
As such, I think it would get 1 mark.
3.a (2 marks)
Describe two chemical barriers that could be present in a plant that is protecting itself from an invading pathogen.
What I wrote:
Chemicals containing antibiotics that target bacteria.
Releases toxins that destroy the pathogen and prevent them from reproducing.
I was wondering whether 'destroying the pathogen' would be too specific and too exact, if you know what I mean? Are these two points valid? What else could I add to my answer?
I just wanted some feedback on my answers as I'm not sure if they are correct and yes I did check the examiner's report.
Thanks in advance, guys!
This last one seems pretty good. however, instead of saying antibiotics that 'target' the bacteria, it might be more correct if you say antibiotics that kill or inhibit the growth of bacteria.