Login

Welcome, Guest. Please login or register.

March 29, 2024, 07:13:37 pm

Author Topic: VCE Biology Question Thread  (Read 3571461 times)  Share 

0 Members and 8 Guests are viewing this topic.

Sine

  • Werewolf
  • National Moderator
  • Great Wonder of ATAR Notes
  • *****
  • Posts: 5135
  • Respect: +2103
Re: VCE Biology Question Thread
« Reply #10905 on: October 22, 2018, 10:51:29 pm »
+2
Could someone explain multiple choice question 25 (2013 exam)? The examiner report does not include any comments. Thanks!

Edit: One more question sorry! If I wrote for question 1a and b short answer (2013 exam) fermentation instead of anaerobic respiration, when the question was talking about yeast, would I get the mark? The examiners report does not state it.
Question 25 2013

So, all the children have different blood groups A, B, AB and O.
The two most important ones are AB and O.
AB tells us that one parent has at least 1 IA allele and the other has at least 1 IB allele. The O child means that each parent also as the i allele. Thus the genotypes of the parents are IAi and IBi thus the blood types are A and B.

Assessors report says 50% said option A which is wrong so a tough question.

Q1a and b

For saying fermentation I probably wouldn't give full marks since the key words were "anaerobic".

When describing the humoural response, how are you supposed to differentiate between the antigen attaching to naive B cell pathway and the helper T cell releasing cytokines to activate B cells pathway.
Not exactly sure what you mean here - you need both of these events in the humoral repsonse (or at least for a fully fledged humoral response).

When are you guys doing the 2017 VCAA exam? I'm thinking of doing it either tomorrow or this saturday (can't do any day in between as i have 1/2 exams haha). Just trying to balance out (1) having sufficient time to review any gaps identified after exam and (2) peak performance when exam rolls around.

What do you guys recommend?
Probably recommend doing it a couple days out from the actual exam so that you have time to review it and relax before your exam.

« Last Edit: October 22, 2018, 10:58:23 pm by Sine »

$noopDodd

  • Trailblazer
  • *
  • Posts: 29
  • Respect: +3
Re: VCE Biology Question Thread
« Reply #10906 on: October 22, 2018, 10:59:53 pm »
0
In reference to NHT 18 q1a:
When bubbles are produced by an Elodea plant underwater, I understand that they come from O2 produced in photosynthesis, but can they also be from CO2 produced from aerobic respiration?
Solutions just say that they are O2 bubbles, makes no mention of aerobic respiration. Is CO2

For allopatric speciation questions (3-4 marks), is it necessary to stress that: new alleles are produced by mutations, and it is these new alleles which allow for some individuals to be at a selective advantage in their environments - I haven't seen reference to mutations for these types of questions in any past papers but this one...

Also, what are some possible concerns of gene editing in humans IF it is done correctly? I've only got answers for concerns where it isn't done correctly e.g. incorrect DNA edits leading to disease, passed down etc.

When you state a hypothesis, do you say the dependent variable as what you specifically measure or what that represents?
e.g. If the light intensity is increased, the "O2 concentration is increased"  or "rate of photosynthesis is increased"

Thanks!
2018: Biology
2019: English, Mathematical Methods, Specialist Mathematics, Chemistry, MUEP Chem

2020: Latrobe Dent

juntyhee

  • Adventurer
  • *
  • Posts: 23
  • Respect: +5
Re: VCE Biology Question Thread
« Reply #10907 on: October 22, 2018, 11:12:50 pm »
+8
In reference to NHT 18 q1a:
When bubbles are produced by an Elodea plant underwater, I understand that they come from O2 produced in photosynthesis, but can they also be from CO2 produced from aerobic respiration?
Solutions just say that they are O2 bubbles, makes no mention of aerobic respiration. Is CO2

For allopatric speciation questions (3-4 marks), is it necessary to stress that: new alleles are produced by mutations, and it is these new alleles which allow for some individuals to be at a selective advantage in their environments - I haven't seen reference to mutations for these types of questions in any past papers but this one...

Also, what are some possible concerns of gene editing in humans IF it is done correctly? I've only got answers for concerns where it isn't done correctly e.g. incorrect DNA edits leading to disease, passed down etc.

When you state a hypothesis, do you say the dependent variable as what you specifically measure or what that represents?
e.g. If the light intensity is increased, the "O2 concentration is increased"  or "rate of photosynthesis is increased"

Thanks!

1\ Good point, perhaps, the rate of photosynthesis was much greater than cellular respiration and all the CO2 produced was immediately used up by the chloroplast before appearing as bubbles?

2\ Just saying that there is "a pre-existing variation in a population" should get you the marks, but why not add "due to mutations" just to be sure? Natural selection is a part of allopatric speciation, and in some VCAA papers they've accepted 'natural selection occurred' as a stage, so I don't think its necessary to go into too much detail about the selective advantage bit - something like "different selection pressures in both environments led to the selection of different traits" is probably enough detail for speciation.

3\ May lead to a society less accepting of differences as possible to select for traits, or 'designer babies'. Artificial shifting of genes in humans seen as playing 'God', ethically wrong. Leads to a wealth divide as only the wealthy have access to such technologies?

4\ What you specifically measure. However, to be safe I usually add 'which is indicative of ...'. So "If light intensity increased, then O2 concentration also increases which is indicative of an increase in the rate of photosynthesis".
2018 - Biology [48]

PopcornTime

  • Forum Obsessive
  • ***
  • Posts: 264
  • Respect: +10
Re: VCE Biology Question Thread
« Reply #10908 on: October 22, 2018, 11:29:21 pm »
0
What would the control group be for a photosynthesis and light intensity experiment?

What would the control group be for a photosynthesis and temperature experiment?

What would the control group be for a photosynthesis and co2 concentration experiment?

PhoenixxFire

  • VIC MVP - 2018
  • Honorary Moderator
  • ATAR Notes Legend
  • *******
  • Posts: 3695
  • They/them/theirs
  • Respect: +3102
Re: VCE Biology Question Thread
« Reply #10909 on: October 22, 2018, 11:32:44 pm »
0
What would the control group be for a photosynthesis and light intensity experiment?

What would the control group be for a photosynthesis and temperature experiment?

What would the control group be for a photosynthesis and co2 concentration experiment?
Depends what the specific conditions of the experiment are. For the second and third ones it would probably in normal conditions - so room temperature and atmospheric CO2. For the first one you would probably have a plant with no light.
2019: B. Environment and Sustainability/B. Science @ ANU
2020: Just Vibing
2021: B. Paramedicine/B. Nursing @ ACU Canberra

Scribe

  • Forum Regular
  • **
  • Posts: 69
  • Respect: 0
Re: VCE Biology Question Thread
« Reply #10910 on: October 23, 2018, 08:06:57 am »
0
Hey guys,

In the extrinsic apoptosis pathway, where does the death ligand come from? Also, is the receptor specific for each cell? If not, what is stopping the ligand from binding to another cell that is similar and inducing apoptosis?

Thanks as always!

PhoenixxFire

  • VIC MVP - 2018
  • Honorary Moderator
  • ATAR Notes Legend
  • *******
  • Posts: 3695
  • They/them/theirs
  • Respect: +3102
Re: VCE Biology Question Thread
« Reply #10911 on: October 23, 2018, 08:32:09 am »
+2
Hey guys,

In the extrinsic apoptosis pathway, where does the death ligand come from? Also, is the receptor specific for each cell? If not, what is stopping the ligand from binding to another cell that is similar and inducing apoptosis?

Thanks as always!
Hey,
You don’t need to know this for VCE (I assume you know that, but just in case you didn’t)

I’m pretty sure the death ligand comes from cytotoxic T cells or natural killer cells (and maybe others?). I got taught that it’s contact-dependant signalling - so it only affects the targeted cell. Not really sure how contact dependant signalling works though haha
2019: B. Environment and Sustainability/B. Science @ ANU
2020: Just Vibing
2021: B. Paramedicine/B. Nursing @ ACU Canberra

vox nihili

  • National Moderator
  • Great Wonder of ATAR Notes
  • *****
  • Posts: 5343
  • Respect: +1447
Re: VCE Biology Question Thread
« Reply #10912 on: October 23, 2018, 10:07:44 am »
+3
Hey,
You don’t need to know this for VCE (I assume you know that, but just in case you didn’t)

I’m pretty sure the death ligand comes from cytotoxic T cells or natural killer cells (and maybe others?). I got taught that it’s contact-dependant signalling - so it only affects the targeted cell. Not really sure how contact dependant signalling works though haha

Yep, this is right :)

Basically anything can be a death ligand too, provided there is a receptor for it that triggers apoptosis. The ordinary method would be by contact-dependent signalling though, otherwise you'd have basically all cells dying at once. There are some special cases about how this happens more generally but we definitely don't need to worry about this in VCE :)
2013-15: BBiomed (Biochemistry and Molecular Biology), UniMelb
2016-20: MD, UniMelb
2019-20: MPH, UniMelb
2021-: GDipBiostat, USyd

marangutan

  • Trailblazer
  • *
  • Posts: 30
  • Respect: 0
Re: VCE Biology Question Thread
« Reply #10913 on: October 23, 2018, 04:51:07 pm »
0
Can anyone explain the purpose of finding out the F2 generation?

PopcornTime

  • Forum Obsessive
  • ***
  • Posts: 264
  • Respect: +10
Re: VCE Biology Question Thread
« Reply #10914 on: October 23, 2018, 04:52:18 pm »
0
Primate traits?
- colour vision
- pentadactylism
- mobile arms
- forward facing eyes
- warm blooded?

What about hominoid traits?

Anything else for the above?


PhoenixxFire

  • VIC MVP - 2018
  • Honorary Moderator
  • ATAR Notes Legend
  • *******
  • Posts: 3695
  • They/them/theirs
  • Respect: +3102
Re: VCE Biology Question Thread
« Reply #10915 on: October 23, 2018, 07:17:55 pm »
+1
Can anyone explain the purpose of finding out the F2 generation?
Depends on the question. Generally to work out the alleles of the parents (by working backwards in a punnet square). Do you have a question on it? (Also, welcome to AN ;D)

Primate traits?
- colour vision
- pentadactylism
- mobile arms
- forward facing eyes
- warm blooded? Lots of animals are warm-blooded - not a primate thing

What about hominoid traits?

Anything else for the above?

From my notes:
Primates are distinguished by:
•   Opposable thumb on a 5-digit hand
•   Flat nails
•   Sensitive fingertips
•   Large, forward facing eyes
•   Colour vision
•   Protective bone at the outer side of the eye socket
•   Large brains compared to body size
•   Sexual dimorphism

Hominoids are distinguished by:
•   No tail
•   Molars with 5 cusps
•   Rip cage is flat not rounded
•   Locomotion by tree swinging, knuckle walking, or bipedalism
•   Posture is fully or partially erect, allowing use of hands

Hominins are distinguished by:
•   Bipedal
•   Fewer and smaller teeth
•   Flat face
•   Lack of heavy brow ridges
•   Large cranial capacity
•   Make tools
•   Use language and/or art
•   Are self aware
2019: B. Environment and Sustainability/B. Science @ ANU
2020: Just Vibing
2021: B. Paramedicine/B. Nursing @ ACU Canberra

galaxy21

  • Trendsetter
  • **
  • Posts: 150
  • Respect: +23
Re: VCE Biology Question Thread
« Reply #10916 on: October 23, 2018, 08:03:38 pm »
0
Hi, so I am a little bit confused about glycoproteins and glycolipids.
I get that glycoproteins are carbohydrate groups that are attached to peripheral proteins on the plasma membrane, whereas glycolipids are attached to a phospholipid, but what is the best way to describe their function in an exam. Isn't one of them MHC markers? And are these also the extracellular receptors on the cell, or is that something else?
2018 - Biology, Further
2019 - English, Chemistry, Methods, Health and Human Development
2020 - Bachelor of Science (Melbourne Uni)

marangutan

  • Trailblazer
  • *
  • Posts: 30
  • Respect: 0
Re: VCE Biology Question Thread
« Reply #10917 on: October 23, 2018, 08:05:18 pm »
0
Depends on the question. Generally to work out the alleles of the parents (by working backwards in a punnet square). Do you have a question on it? (Also, welcome to AN ;D)

What do you mean by working out the alleles of the parents? Is this in reference with the parent generation or F1?
I don't have a specific question on it but I really can't see why it's needed.

PhoenixxFire

  • VIC MVP - 2018
  • Honorary Moderator
  • ATAR Notes Legend
  • *******
  • Posts: 3695
  • They/them/theirs
  • Respect: +3102
Re: VCE Biology Question Thread
« Reply #10918 on: October 23, 2018, 08:14:30 pm »
0
Hi, so I am a little bit confused about glycoproteins and glycolipids.
I get that glycoproteins are carbohydrate groups that are attached to peripheral proteins on the plasma membrane, whereas glycolipids are attached to a phospholipid, but what is the best way to describe their function in an exam. Isn't one of them MHC markers? And are these also the extracellular receptors on the cell, or is that something else?
You won't ever have to describe their function - it's not on the study design

What do you mean by working out the alleles of the parents? Is this in reference with the parent generation or F1?
I don't have a specific question on it but I really can't see why it's needed.
Either. So say you have the F1 generation and you know their phenotype but not their genotype, then by finding out the F2 generation (you wouldn't be able to predict it, the question would give you that) then you can work out the genotype of F1 (due to the percentages of different alleles in F2). You could then do the same thing again to figure out the parents genotype/phenotype now that you know the F1 generations genotypes - although I don't know why you would want to.
2019: B. Environment and Sustainability/B. Science @ ANU
2020: Just Vibing
2021: B. Paramedicine/B. Nursing @ ACU Canberra

marangutan

  • Trailblazer
  • *
  • Posts: 30
  • Respect: 0
Re: VCE Biology Question Thread
« Reply #10919 on: October 23, 2018, 08:22:31 pm »
0
Either. So say you have the F1 generation and you know their phenotype but not their genotype, then by finding out the F2 generation (you wouldn't be able to predict it, the question would give you that) then you can work out the genotype of F1 (due to the percentages of different alleles in F2). You could then do the same thing again to figure out the parents genotype/phenotype now that you know the F1 generations genotypes - although I don't know why you would want to.

Ah ok. Thank you <3
For the P generation, is there a reason why you have to specifically cross a dominant purebred with a recessive purebred or is this pretty much like a test cross?