1) What is the purpose of a vacuole in a plant? Do I need to know anything aside from that it maintains the correct osmotic pressure?
3) What is the difference between an organelle being made of membrane vs "membrane bound"?
1. Nope.
3. Depends on the context. Maybe nothing, could be comparing something like the ER and golgi body to something like a chloroplast - all three are membrane bound but ER and golgi are made of membrane.
Thanks For question 1, I was just wondering whether the glycolipids and glycoproteins should face the extracellular environment not the intracellular environment.
I would think so – but imo if you just switched the names then none of the answers would be correct.
For this question (VCAA 2006 Exam 1, q8c), can someone explain why a few years after HIV infection, the patient has swollen lymph nodes? The little blurb thingy in the question is attached for a bit of context. The VCAA answer didn't really give much of an explanation.
Would the swollen lymph nodes occur as a result of increased production of T cells (not even sure if this is correct lol, but my reasoning for this is that the body detects that the T cells are not functioning properly and tries to make more) or due to more immune cells in that area (but which types of leukocytes would this be? I would assume not lymphocytes as the adaptive immune response is impaired due to T-helper cells not being able to activate the humoral/cell-mediated response).
Lol while typing this I just thought of two more questions: to my understanding, HIV only affects Helper-T cells, is this correct (because the question just refers to T cells in general), and are antibodies effective against viruses?
1). I’m not really sure what they want here (gotta love assessors reports
) From what they’ve written on the assessors report I don’t think they’re after an answer that specific. I think you’d be right if you wrote anything about how they’re swollen because of the virus (I’m kind of just guessing, but I don’t think they’d want a specific reason). Maybe send Vox Nihili a msg and ask if he knows. He’s probably really busy atm but he might be able to explain it.
2). Yep it’s just Th cells.
3). Nope. Antibodies can’t get inside cells and viruses live inside cells so they’re not effective against them (at least for VCE, in reality humoral immunity is activated because of the fragments of virus outside of cells, but don’t talk about that, just talk about cell-mediated immunity).
Is it important to know all the different class antibodies and their purpose?.. (as in IgE, IgG ...and so on)
Not necessary, but you should know that IgE antibodies are involved in the allergic response 
And that IgG are the most common.
Hello again!
I’ve got a bunch of questions and I though it might be easier to posters them separately instead of in a massive chunk...
Sooooo...
1. Those gel electrophoresis questions when they give you a bunch of statements like individual 1 and 3 are the parents and 2 and 4 are the children.. any tips? Cos sometimes I feel like all the possible answers look the same? Know what I mean? As in answers A or C or whatever are both valid... so how can you fully conclude which one is correct?? Maybe I should post a pic if that would help?? (It’s a 35 btw)
2. Also, any tips for identifying high/med/low levels of Cam or BMP 4, cos they are a bit tricky also...
3. What are positive/negative controls?! Are they relevant?!
4. Second Line of defence is the non specific immune stuff right? So Natural Killer Cells, Interferons, Phagocytes... anything else I should know??
5. See the attached pic regarding HIV. I had to draw a possible shape for a fusion inhibitor drug right, so I drew an arrow kinda thing. Like a rectangle w a triangle no one end. Kinda like this if you turned it to the left. That was wrong. Apparently the answer is a plain rectangle. Why? I mean I guess a rectangle would work but surely my answer is right too?
6. Could somebody please explain the differences bw an antiviral drug and monoclonal antibodies please?
I know this is a tonne of questions but I really don’t know who to ask 
please help 
(BTW this thing doesn’t let me post pics straight from my iPad, cos it’s apparantly the wrong kinda file... whyyyyyy)
1. You’ve just got to match them up. Get out your coloured pens and start circling lines. If you have both of the parents then all of the child’s markers should match those of the parents – half should match one parent, half should match the other. If you’ve only got one parent then half of the child’s markers need to match half of the parent’s.
2. Do you have a question on this? I’d say it’d just be a case of ‘big beak = high BMP4’
3. Yep they’re relevant. A positive control is something that is known to react, a negative control is something that is known to not react. So for example if you’re testing the effect of different light colours on the rate of photosynthesis a positive control would be white light and a negative control would be no light. They’re used to make sure that your experiment is working correctly. So for example if the plant doesn’t grow under the white light then you know something is wrong (maybe the plant is dead, or hasn’t been given enough water or something like that).
4. Dendritic cells, macrophages, mast cells, natural Killer cells, interferons, complement proteins, neutrophils.
5. So long as your shape would have fit then it’s correct too. They don’t necessarily draw all possible answers.
6. An antiviral drug is something that designed to fit into a specific spot. So, like the shape you drew above. It’ll normally be something that either stops a virus from entering or leaving a cell.
Monoclonal antibodies are produced in a lab. They’re clones (so they’re identical) to each other – they all have the same antigen-specificity (they can bind the same antigen). They can be used for many different things, such as targeting of cancer drugs – the monoclonal antibody will have the drug attached to it, it will then be injected into the patient body and will find something to bind to. It would have been designed to bind to the cancer/something near/associated with the cancer, delivering the drug straight to where it’s needed.
1. If a person is infected with a virus, what techniques can be used to identify the virus?
2. Do lysozymes lyse bacterial cell walls?
3. Do complement proteins lyse bacterial cell membranes?
4. Why is cell mediated immunity involved in tissue rejection and not humoral?
5. I can't succinctly describe why it doesn't matter about an initial measurement of something if the DV is % change. for example, it doesn't matter what initial biomass of plant is, and dv is measuring % change of biomass of plant. Any advice?
1. You just get a blood sample and then use one of these: (most likely the last one)
-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)
2. Yeah sorta. They break apart one of the key components that keeps bacterial walls intact.
3. Yep.
4. Because it deals with cells. The foreign tissue is treated as non-self, the same as it would be if it was affected by a virus.
5. Maybe just write that the DV is measuring change in relation to the initial measurement, so it doesn’t matter what the initial measurement is (depends on what specifically the question says though).
2017 Exam question 9bii
Shouldn't there be two BamHI recognition sites at the start and end of the human gene in the plasmid? Is that wrong or are you just not required to put it in?
Yep there should be. I don’t know why they didn’t put it in.
For question 6b, could I also mention the splicing of introns and joining of exons because it says molecule W has a different nucleotide sequence from the ‘coding section’ of the DNA molecule?
I think you could but I don’t think it’s necessary. In this case when they say that it has a different nucleotide sequence I think they’re just talking about it being RNA and being complementary to the DNA rather than being significantly different. Also nowhere in the stem of the question does it mention it, so I don’t think it’d really be wrong, but it’s probably a waste of time to talk about it.
Also - people who are posting questions in the middle of the night, please sleep instead. Getting an extra practice exam done isn't worth the effects of sleep deprivation
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