VCE Biology Question Thread

[sophiie]

Hey, how would you describe the difference between precision and accuracy?
Thanks.

[vox nihili]

Hey, how would you describe the difference between precision and accuracy?
Thanks.

What do you understand about the differences already? This is a really tricky area so trying to put what you know in your own words first is useful

Welcome to AN!

[persistent_insomniac]

How do you know if a question is talking about the humoral response or cell-mediated response? For example, in the unit 3 VCAA 2008 exam, one of the questions was 'describe the process of tissue-rejection.....' and the answer was talking about the cell-mediated response? Or is the cell-mediated response just activated in cases like this? Thanks!

[Sine]

How do you know if a question is talking about the humoral response or cell-mediated response? For example, in the unit 3 VCAA 2008 exam, one of the questions was 'describe the process of tissue-rejection.....' and the answer was talking about the cell-mediated response? Or is the cell-mediated response just activated in cases like this? Thanks!

Humoral response generally impacts the extracellular pathogens
Cell mediate response generally impacts the infected cells (intracellular pathogens)

Tissues are actual cells so it's going to be targeted by the cell-mediated response

[Scribe]

Do we need to know about the ABO blood group system (eg. Question 25 MC, 2013 exam)?
Thanks!

[C14M8S]

1) How is RNA polymerase produced? The TSSM 2018 practice exam states that it is synthesised by promoter genes, which seems odd and incorrect.
2) Is there a simple way to recognize tertiary protein structure vs secondary structure from 3D models? Are proteins automatically tertiary once they have multiple secondary structures/curvature in their strand?

[Sine]

Do we need to know about the ABO blood group system (eg. Question 25 MC, 2013 exam)?
Thanks!

question assumes very little knowledge  and some students could infer on blood types so I don't think so

It is still good to understand stuff like the blood type A means I^aI^a or I^ai genotypes and O blood group is ii.

The most important part would be that AB blood type is codominant with both A and B alleles.

[vox nihili]

1) How is RNA polymerase produced? The TSSM 2018 practice exam states that it is synthesised by promoter genes, which seems odd and incorrect.
2) Is there a simple way to recognize tertiary protein structure vs secondary structure from 3D models? Are proteins automatically tertiary once they have multiple secondary structures/curvature in their strand?

1) RNA polymerase is made in the same way as any other protein.
2) Presumably you're referring to the question a couple of years back that showed a model of an immunoglobulin and asked you to identify beta-sheets and alpha helices. Tertiary structure is the overall shape of the protein, whereas secondary structures are repeated elements in the structure of the protein. Secondary structures are the repeated twists (alpha-helices) and folds (beta-sheets) that help form the basis of the tertiary structure.
When you're looking at a model, any repeated elements (however they might be depicted) will be secondary structures. The overall shape is tertiary. By convention beta-sheets are represented as arrows and alpha-helices are represented as helices (twists).

[C14M8S]

1) RNA polymerase is made in the same way as any other protein.

How is the mRNA for RNA polymerase formed without RNA polymerase being initially present, though? Is it just present when the cell divides by default?

[vox nihili]

How is the mRNA for RNA polymerase formed without RNA polymerase being initially present, though? Is it just present when the cell divides by default?

Asking the tough questions! The zygote starts off with the RNA polymerase from the egg, then every cell from then on gets their RNA polymerase from their parent cell.

[Scribe]

question assumes very little knowledge  and some students could infer on blood types so I don't think so

It is still good to understand stuff like the blood type A means I^aI^a or I^ai genotypes and O blood group is ii.

The most important part would be that AB blood type is codominant with both A and B alleles.

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.

[Agimo]

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.

[persistent_insomniac]

What exam score (roughly) would achieve a study score of 40? Is 90%+ considered A+

[C14M8S]

What exam score (roughly) would achieve a study score of 40? Is 90%+ considered A+

Last year the mark for an A+ was 95/120, or 79%. If you could score around that with A+ SACs (scaled), then you'd get a 40.

[juntyhee]

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?