HSC Biology Question Thread

[Sssssrr]

From what I understand, the response is a result of the adaptation. From my example, the Red Kangaroo places it's tail underneath it's body when the ambient temperature rises to reduce SA:V ratio, and decrease heat absorption from the sun - the behavioural adaptation allows for the response (placing tail under body) in order to decrease temperature and regulate temperature. So they are kind of two peas in a pod to an extent.

Happy to clarify if this doesn't make sense aha.

That helps a lot, thanks

[aimbotted]

hi guys, could someone explain to me the difference between cell mediated immunity vs anti-body mediated immunity? thanks

[jakesilove]

hi guys, could someone explain to me the difference between cell mediated immunity vs anti-body mediated immunity? thanks

Anti-body

Produced by B cells, which match specific antigens. Antigens generate an anti-body response.

Cell mediated

You've got cells in your body, like natural killer cells. Cell mediated immunity doesn't get better over time. Everyone has some mediated immunity. I think. Let me check that

Answer from the Med student sitting next to me

Jake

[marynguyen18]

whats the different between a B and T cell?

[jakesilove]

whats the different between a B and T cell?

According to google: T cells can be distinguished from other lymphocytes, such as B cells and natural killer cells, by the presence of a T-cell receptor on the cell surface.

Jake

[g98]

Hi,
There are several dot points in the Biotechnology syllabus that are worded like this:

describe one example from the following applications of biotechnology in medicine:
-tissue engineering using skin transplantation as an example
-gene delivery by nasal sprays
-production of a synthetic hormone, such as insulin

Does this mean we need to know one example from each of the three or does it mean we need to know one of the three but not the others? I hope that makes sense!
Thanks

[g98]

Hi, quick question for any who does the Biotechnology option:
what are monoclonal antibodies and recombinant vaccines and what do we need to know about each?
Thanks!

[Sssssrr]

Hey can someone please help me with questions 19 and 20, I've attached them
Thanks

[cajama]

Hello
I'm kind of confused by the sample answer for this question (2011 HSC Biology Q.30 b. -- sorry if the screenshot doesn't appear, it would not appear on preview):
"If the temperature of the animal is determined only by the ambient temperature, the animal would lose temperature at a similar rate to which it gained the temperature, rather than retaining the heat" - Success One | HSC Biology 2013 ed.

My own answer was basically: Body temp. is not controlled by ambient temp as the avg. body temp of the reptiles, shown in the graph, correlates with the day's temperatures where it is often highest during the early afternoon.

I can see flaws in my answer as I don't fully have evidence for the change in temperature(weather) during the day and that correlation does not always imply causation, but yeah I wasn't really sure how to answer this question + sample answer was a little confusing haha. Thankyou in advance to whoever replies! 

--
Also, general question for all science exams, can we abbreviate words in the exam i.e. temperature to temp., environment to enviro., generation to gen.? It just helps to save time 

[cajama]

Hey can someone please help me with questions 19 and 20, I've attached them
Thanks

Hello, I'm probably wrong in these answers and I'm not really a reliable source of help but I tried the questions:
For Q.19 I chose A because basically it would take time to produce the enzyme. If it was gradual, as one enzyme denatures, another one may be on its way to be produced. If it was a rapid change, all the currently functioning enzymes would die out and as it takes time to produce enzymes, there wouldnt be any enzymes that would maintain metabolic activity and the fish would die??

For Q.20 I thought maybe it would be B: the change in temperature in the environment affects the production of the enzymes (the phenotype being the ability to produce four enzymes at different temperatures??)
Not D: because the case study doesn't really say anything about the body temperature of the fish and it only talks about the temperature of the environment, A: because the case study doesn't mention substrates, C: it's not really a limitation for the fish if they can still survive at such a wide temperature variation as long as the four enzymes can still function respective of their temperature ranges.
"idk tho"
Please correct me if I'm wrong haha I tried 

[vox nihili]

Hello, I'm probably wrong in these answers and I'm not really a reliable source of help but I tried the questions:
For Q.19 I chose A because basically it would take time to produce the enzyme. If it was gradual, as one enzyme denatures, another one may be on its way to be produced. If it was a rapid change, all the currently functioning enzymes would die out and as it takes time to produce enzymes, there wouldnt be any enzymes that would maintain metabolic activity and the fish would die??

For Q.20 I thought maybe it would be B: the change in temperature in the environment affects the production of the enzymes (the phenotype being the ability to produce four enzymes at different temperatures??)
Not D: because the case study doesn't really say anything about the body temperature of the fish and it only talks about the temperature of the environment, A: because the case study doesn't mention substrates, C: it's not really a limitation for the fish if they can still survive at such a wide temperature variation as long as the four enzymes can still function respective of their temperature ranges.
"idk tho"
Please correct me if I'm wrong haha I tried 

Well reasoned; both answers are correct imo

[kevin217]

Hey guys I got a question. When we are solving sex-linked inheritance do we always assume that the X chromosome is the one carrying condition and never the Y chromosome?

[Skidous]

Hey guys I got a question. When we are solving sex-linked inheritance do we always assume that the X chromosome is the one carrying condition and never the Y chromosome?

That is correct, the infection is always carried on the X chromosome, this is why males can only inherit or not inherit a condition whilst females can be carriers (condition carried on only one X-chromosome)

[vox nihili]

Hey guys I got a question. When we are solving sex-linked inheritance do we always assume that the X chromosome is the one carrying condition and never the Y chromosome?

I'm not particularly clear on what you're expected to know in HSC, but of course sex-linked inheritance could involve genes on the Y-chromosome. Pretty much as easy as it gets though. Passed from father to son to son to son to son to son to son, can't skip a generation, never seen in females blah blah

[Skidous]

I'm not particularly clear on what you're expected to know in HSC, but of course sex-linked inheritance could involve genes on the Y-chromosome. Pretty much as easy as it gets though. Passed from father to son to son to son to son to son to son, can't skip a generation, never seen in females blah blah

Yeah I got told about Y linked diseases but there isn't anything on that for the HSC so it's not exactly necessary