VCE Biology Question Thread

[valjaybj]

Hi,
Hope all's well! Logically speaking - if the body recognised it as non-self - it would attack it..... which would probably (hopefully) kill the cancer cell. I think that's why its so hard to treat - as the immune system doesn't recognise it as non-self. The holy grail of cancer research is finding a way to selectively kill only the cancer cell. What they are looking into more recently is "immunotherapy" - which is essentially just marking the cell as foreign, and getting the immune system to kill it. (I think).

So the sort answer - it would be "non-self". Or if it was "self", it would have mechanisms to defeat/escape lymphocytes. But as with anything in bio - there is so much complexity. For VCE level, I think the above explanation is ok.

Having said that, I haven't read the new study design (and my bio is a bit rusty). Idk.
Hope this helps

hey, thanks!! yeah im thinking the same, in terms of understanding that it'd be non-self in order to actually get rid of it (but then in reality it's probably recognised as a self-antigen therefore evading the immune system). thanks for clearing that up!

[Bri MT]

hi! does anyone know whether cancerous antigens on MHC I markers are recognised as self or non-self? from my understanding it's non-self (but i did a google search and it says self so now im confused)

Cancerous cells can display tumor associated antigens or tumor specific antigens, which allow the immune system to recognise them as harmful despite being self cells. Some of them are recognised as foreign, others are not but are still able to be identified as tumour associated because of how they are expressed (e.g. at too high a level).

Hope this helps

[emilydd123]

Hey guys,
What would you recommend the best way to revise for unit 3 bio is? I've started doing practise U3 questions but I feel like I'm not covering everything. I've bene using notes to answer questions but was wondering if there's anything else I should be doing, besides writing notes (waste of time)?
Thanks so much!

[beep boop]

Hi emilydd123!

Even tho I didn't do well in bio, I do have some tips. What I would reccomend printing out the sd and using that as a checklist to see what you're lacking in, find out your weakest and stronger areas etc.

Also start doing some prac papers. You don't have to get them all right, now. It does give you a good feel of what an exam q is and what they like to ask.

Hope this helps,
beep boop

[biology1234]

hey, why are dendritic cells better antigen presenting cells than macrophages?
thanks

[Billuminati]

hey, why are dendritic cells better antigen presenting cells than macrophages?
thanks

DCs can activate naive T-cells whereas macrophages can't. Macrophages can only present to Th cells that are already activated