Welcome, Guest. Please login or register.

August 21, 2019, 05:38:04 pm

Author Topic: VCE Biology Question Thread  (Read 1307027 times)  Share 

0 Members and 4 Guests are viewing this topic.

MAGGOT

  • Trendsetter
  • **
  • Posts: 110
  • Respect: +2
Re: VCE Biology Question Thread
« Reply #10350 on: May 27, 2018, 02:52:17 pm »
0
Are blood group or blood related case studies important?

PhoenixxFire

  • VIC MVP - 2018
  • Moderator
  • ATAR Notes Superstar
  • *****
  • Posts: 2633
  • Bad puns are how eye roll
  • Respect: +1944
Re: VCE Biology Question Thread
« Reply #10351 on: May 27, 2018, 02:53:52 pm »
0
Are blood group or blood related case studies important?
Not anymore - it was on the previous study design
2019: B Environment and Sustainability/B Science @ ANU

FabAsianZung

  • Adventurer
  • *
  • Posts: 19
  • Respect: 0
Re: VCE Biology Question Thread
« Reply #10352 on: May 27, 2018, 04:32:15 pm »
0
Can anyone explain step-by-step on how innate and adaptive immune system respond to a bacteria and a virus? In order of what happens first please!

Thanks beforehand!
Eh? I passed?

*look at front page and an A+ is written*

Abi21

  • Adventurer
  • *
  • Posts: 24
  • Respect: 0
Re: VCE Biology Question Thread
« Reply #10353 on: May 27, 2018, 07:13:15 pm »
0
At the end of the year, do schools submit one ranking per student for bio or two per student (one for unit 3 and one for unit 4)

PhoenixxFire

  • VIC MVP - 2018
  • Moderator
  • ATAR Notes Superstar
  • *****
  • Posts: 2633
  • Bad puns are how eye roll
  • Respect: +1944
Re: VCE Biology Question Thread
« Reply #10354 on: May 27, 2018, 07:15:18 pm »
0
At the end of the year, do schools submit one ranking per student for bio or two per student (one for unit 3 and one for unit 4)
2. Unit 3 will be GA1, Unit 4 will be GA2 and the exam will be GA3
2019: B Environment and Sustainability/B Science @ ANU

darkz

  • MOTM: APR 18
  • Forum Obsessive
  • ***
  • Posts: 275
  • Respect: +94
Re: VCE Biology Question Thread
« Reply #10355 on: May 27, 2018, 07:16:31 pm »
0
At the end of the year, do schools submit one ranking per student for bio or two per student (one for unit 3 and one for unit 4)

Not too sure, but when I asked my teacher, he said that they just submit one ranking overall for the entire year
2018: Biology [50 + Prems], Mathematical Methods
2019: English, Latin, Chemistry, Specialist Mathematics
Free Biology Unit 3/4 Notes

PhoenixxFire

  • VIC MVP - 2018
  • Moderator
  • ATAR Notes Superstar
  • *****
  • Posts: 2633
  • Bad puns are how eye roll
  • Respect: +1944
Re: VCE Biology Question Thread
« Reply #10356 on: May 27, 2018, 07:18:43 pm »
+3
Not too sure, but when I asked my teacher, he said that they just submit one ranking overall for the entire year
Your teacher's wrong - for subjects with 2 exams (like maths) you get 1 rank, for subjects with 1 exam you get two separate ranks
2019: B Environment and Sustainability/B Science @ ANU

Abi21

  • Adventurer
  • *
  • Posts: 24
  • Respect: 0
Re: VCE Biology Question Thread
« Reply #10357 on: May 27, 2018, 07:24:13 pm »
0
Your teacher's wrong - for subjects with 2 exams (like maths) you get 1 rank, for subjects with 1 exam you get two separate ranks
okay thanks, I've heard different answers from different people.

MAGGOT

  • Trendsetter
  • **
  • Posts: 110
  • Respect: +2
Re: VCE Biology Question Thread
« Reply #10358 on: May 27, 2018, 07:33:24 pm »
0
Your teacher's wrong - for subjects with 2 exams (like maths) you get 1 rank, for subjects with 1 exam you get two separate ranks

So for a subject with 1 exam like bio, the 2 separate rankings are for unit 3 and unit 4?

PhoenixxFire

  • VIC MVP - 2018
  • Moderator
  • ATAR Notes Superstar
  • *****
  • Posts: 2633
  • Bad puns are how eye roll
  • Respect: +1944
Re: VCE Biology Question Thread
« Reply #10359 on: May 27, 2018, 07:34:21 pm »
0
So for a subject with 1 exam like bio, the 2 separate rankings are for unit 3 and unit 4?
yep
2019: B Environment and Sustainability/B Science @ ANU

vox nihili

  • National Moderator
  • Great Wonder of ATAR Notes
  • *****
  • Posts: 5266
  • Respect: +1360
Re: VCE Biology Question Thread
« Reply #10360 on: May 27, 2018, 07:51:38 pm »
0
Your teacher's wrong - for subjects with 2 exams (like maths) you get 1 rank, for subjects with 1 exam you get two separate ranks

Backing this up. Absolutely right PF
MED INTERVIEW TUTORING PM to secure your place early, as they fill up quickly!

Join ATARNotes Footy Tipping

2013-15: BBioMed (Biochemistry and Molecular Biology), UniMelb
2016-20: MD, UniMelb
2019: MPH, UniMelb
Year I: BIOL10002 BIOL10003 CHEM10006 MAST10011 MAST10016 PHYC10007 SPAN10001 SPAN10002
Year II: BCMB20005 BIOM20001 BIOM20002 CLAS10022 GENE20001 SPAN20020 SPAN30014
Year III: BCBM30001 BCMB30002 BCMB30010 BIOM30001 BIOM30002 PHRM30008

PhoenixxFire

  • VIC MVP - 2018
  • Moderator
  • ATAR Notes Superstar
  • *****
  • Posts: 2633
  • Bad puns are how eye roll
  • Respect: +1944
Re: VCE Biology Question Thread
« Reply #10361 on: May 27, 2018, 08:17:04 pm »
+3
Can anyone explain step-by-step on how innate and adaptive immune system respond to a bacteria and a virus? In order of what happens first please!

Thanks beforehand!

Innate
Okay so the innate system responds the same way to both bacteria and viruses- it's non-specific.

Firstly mast cells release histamine. Histamine binds to capillary walls and causes vasodilation (expansion). This causes more blood to go to the area, which causes heat & redness. Histamine also causes capillary walls to become 'leaky' - white blood cells are able to cross the membrane to access the infected area - this causes swelling.

Some of those white blood cells are phagocytes. Neutrophils are an innate phagocyte. They will travel through the area and phagocytose ('eat') anything that is non-self. Macrophages and dendritic cells are also phagocytes however they are also Antigen Presenting Cells (APC's). They will phagocytose foreign material and then use it to trigger the adaptive immune response.

Also part of the innate immune response are complement proteins.  Complement are actually a group of proteins that perform 3 functions.
1. Aid phagocytosis by opsonizing antigens. Basically they make it easier for phagocytes to find antigens - you don't need to know how.
2. Trigger inflammation by attracting neutrophils and macrophages to the area.
3. Form a Membrane Attack Complex - they make holes in bacterial cell walls.

Because of 3. they are most effective against bacteria.

Humoral (extracellular)
This actually occurs for both bacteria and viruses, but if you get a question on viruses you should talk about intracellular immunity.

Humoral immunity involves B cells, and to a lesser extent T helper (Th) cells.

When pathogens are floating throughout the body, bits of them will inevitably break off. These bits are called free antigens, they will end up encountering a naive B cell that can bind to them. When this happens that B cell is said to be 'selected'.

At the same time a macrophage or dendritic cell that has engulfed a pathogen back in the innate immunity stage will present the antigens from that pathogen on its MHC2 markers. It will then travel throughout the body until it find a naive T helper cell that it can bind to. When this happens that Th cell is 'selected'.

The selected B cell and Th cell travel throughout the body trying to find each other. When they do find each other, the B cell will present the antigen it found to the Th cell. If the Th cell can bind to it then they have the same specificity (they've bound the same antigen). The Th cell will release cytokines (a type of signalling molecule). These cytokines stimulate both the Th and B cell (and cytotoxic T cells in cell-mediated immunity) to divide (make copies) and differentiate (into memory cells and active Th/Plasma B cells). Memory Th and B cells stay in the body to fight against any subsequent infection by a pathogen with an identical antigen. The active Th cells will continue to bind antigens from macrophages and dendritic cells. I'm not entirely sure what the purpose of this continuing is - I believe it has something to do with knowing when to stop the immune response? We don't need to know the details for VCE though Plasma B cells make lots and lots of antibodies with the same antigen specificity (shape of their binding site) as the B cell receptors that bound the initial antigen (these receptors are actually antibodies). These antibodies are released and travel throughout the body binding to any complementary antigens they find.

This has a few purposes.
1. It makes the antigens easier for phagocytes to find.
2. It stops virus antigens from entering cells - it makes them too large
3. It can cause agglutination (clumping). Antibodies have 2 identical receptors so they can bind to two antigens and create a clump.

Cell mediated (intracellular)
Cell-mediated immunity involves cytooxic T cells, and to a lesser extent T helper cells.

This only happens with intracellular infections, as well as cancer, transplantation, and autoimmune responses.

Cytotoxic T (Tc) cells regularly travel throughout the body attempting to bind to peptide fragments presented on MHC1.
MHC1 is found on all cells that have a nucleus - that is, all cells except red blood cells. During normal peptide production, fragments are presented to check that they are self - to check that there is no virus or mutations.

When a Tc cell successfully binds to one of these fragments it is 'selected'. The Tc cell will release granzymes (including perforin) that induce apoptosis in the affected cell. When the cytokines from humoral immunity are released by the T helper cell, the Tc cell will divide and differentiate into memory Tc cells, which remain in the body to kill any cell that presents an identical peptide fragment at a later date and active Tc cells. These active Tc cells will have the same antigen specificity (the same shaped receptor) and will travel throughout the body and kill any cells they find that are presenting the same peptide fragment.
I wasn't really sure what you know so I've probably over explained some parts, let me know if any of that doesn't make sense.
In terms of timing Innate occurs first, adaptive overlaps innnate. Humoral and cell-mediated can start in either order but cell-mediated cannot truly occur until cytokines are released from the T helper cell.

@everyone let me know if I messed any of that up
2019: B Environment and Sustainability/B Science @ ANU

Scooby

  • Victorian
  • Forum Leader
  • ****
  • Posts: 619
  • Respect: +28
Re: VCE Biology Question Thread
« Reply #10362 on: May 28, 2018, 01:02:48 am »
+2
At the same time a macrophage or dendritic cell that has engulfed a pathogen back in the innate immunity stage will present the antigens from that pathogen on its MHC2 markers. It will then travel throughout the body until it find a naive T helper cell that it can bind to . When this happens that Th cell is 'selected'.

The selected B cell and Th cell travel throughout the body trying to find each other . When they do find each other, the B cell will present the antigen it found to the Th cell. If the Th cell can bind to it then they have the same specificity (they've bound the same antigen). The Th cell will release cytokines (a type of signalling molecule). These cytokines stimulate both the Th and B cell (and cytotoxic T cells in cell-mediated immunity) to divide (make copies) and differentiate (into memory cells and active Th/Plasma B cells). Memory Th and B cells stay in the body to fight against any subsequent infection by a pathogen with an identical antigen. The active Th cells will continue to bind antigens from macrophages and dendritic cells. I'm not entirely sure what the purpose of this continuing is - I believe it has something to do with knowing when to stop the immune response? We don't need to know the details for VCE though Plasma B cells make lots and lots of antibodies with the same antigen specificity (shape of their binding site) as the B cell receptors that bound the initial antigen (these receptors are actually antibodies). These antibodies are released and travel throughout the body binding to any complementary antigens they find.

This is a really good summary. The parts I've bolded happen usually in lymph nodes - the APC (usually a dendritic cell) will migrate from the site of infection to a lymph node and present peptide therein. B cell activation happens in the lymph node too.

The main reason you have continual activation of Th cells is to provide enough "signal" for activation of your B and Tc cells, which ensures clearance of the pathogen
2012-2013: VCE - Biology [50]
2015-2017: Bachelor of Science (Pharmacology & Physiology) @ Monash
2018-2021: Doctor of Medicine @ Melbourne

Tutoring Biology in 2019. Send me a PM if you're interested! :)

You dont know me

  • Forum Regular
  • **
  • Posts: 54
  • Respect: +30
Re: VCE Biology Question Thread
« Reply #10363 on: May 28, 2018, 08:23:50 pm »
0
Hello fellow people, first time using this so not sure if I have done this or correctly or not, but anyways how should I be preparing/studying for up coming sacs/exams. Should I be creating summaries, or creating mind maps? Thanks  ;D
Currently studying:
-Legal Studies U3
-Biology U3
-Pyschology U3
-General Maths U3
-English U3
Check out my VCE journey

Sine

  • Moderator
  • ATAR Notes Legend
  • *****
  • Posts: 3445
  • NO ARTWORK 23
  • Respect: +781
Re: VCE Biology Question Thread
« Reply #10364 on: May 28, 2018, 08:25:39 pm »
+1
Hello fellow people, first time using this so not sure if I have done this or correctly or not, but anyways how should I be preparing/studying for up coming sacs/exams. Should I be creating summaries, or creating mind maps? Thanks  ;D
Depends on each person, you need to find out what works for you and that is best done by trying multiple techniques.