VCE Biology Question Thread

[Quantum44]

What would you say for a question asking you how to stop a disease in some village (relating to herd immunity im assuming) and the answer being antibiotics i would of thought it would be vaccines can someone explain this to me.

Also has anyone had the immunolgy sac i have it tomorrow and im worried bc so much CONTENT  surely they cant test us on all of this

I assume it is because vaccines cannot be used to treat a disease, only to give immunity to a disease beforehand. Therefore antibiotics would be more effective for patients who are already infected.

Don't worry about your SAC. There is a tonne of content in immunology, but I'm sure if you have studied hard, you will do well.

[vox nihili]

What would you say for a question asking you how to stop a disease in some village (relating to herd immunity im assuming) and the answer being antibiotics i would of thought it would be vaccines can someone explain this to me.

Also has anyone had the immunolgy sac i have it tomorrow and im worried bc so much CONTENT  surely they cant test us on all of this

Just to add to what Quantum44 has already said. You actually protect the population by treating people with antibiotics. Every person you successfully cure is one less person to spread the disease. This particular approach is really critical in a lot of STIs, such as HIV and gonorrhoea.

[vox nihili]

Are complement proteins cytokines? Or are they just proteins working with cytokines? TIA

They're not cytokines. Cytokines are basically paracrines/hormones of the immune system. Complement actually has specific functions, like mediating the death of bacteria or making things tastier for phagocytes.

[rachellang]

Which cells have MHC Class 2 markers? TIA

[vox nihili]

Which cells have MHC Class 2 markers? TIA

Antigen presenting cells. You could google this.

[ardria]

Which cells have MHC Class 2 markers? TIA

You should also know that B cells, dendritic cells and macrophages (both phagocytes) are professional antigen presenting cells. Note that cells with MHC I can present foreign antigens too when they become infected.

Have a look at: https://en.wikipedia.org/wiki/Antigen-presenting_cell#Professional (yes I know, wikipedia)

[Hiea]

When a protein folds, does it literally just... fold? In half or something? Sorry for the weird question, I'm just having trouble visualising the process

[vox nihili]

When a protein folds, does it literally just... fold? In half or something? Sorry for the weird question, I'm just having trouble visualising the process

I didn't listen to the content of this video, but towards the end it shows an animation of a protein folding.

https://www.youtube.com/embed/yZ2aY5lxEGE

Proteins don't really fold in half as you've described. It's more like origami. A series of deliberate, smaller folds that all conspire to make an exact structure. That's how protein folding works, in essence

[ezferns]

Hey everyone, would a pathogen wiping out members of a population be genetic drift (since it is a chance/bottleneck event) or natural selection (since only those resistant are selected for survival)?

[Quantum44]

Hey everyone, would a pathogen wiping out members of a population be genetic drift (since it is a chance/bottleneck event) or natural selection (since only those resistant are selected for survival)?

Well natural selection is a mechanism for evolution that causes a change in allele frequencies due to differential reproductive success in members of a population, whereas genetic drift is a change in allele frequencies due to a random event. Since the hypothetical disease wipes out a subset of the population not randomly, but based on inherent resistance to the pathogen acquired through genetic mutations, it would have to be natural selection.

[ezferns]

Thankyou, that makes sense

[Domek]

Hi there, what to write when explaining the purpose of a control group? I read in the Checkpoints that simply stating 'standard of comparison' is not good enough. I used to think that it is 'to ensure that the independent variable is the only factor causing a change in the reuslts', but I'm not so sure any more. Somebody help? Thanks 

[vox nihili]

Hi there, what to write when explaining the purpose of a control group? I read in the Checkpoints that simply stating 'standard of comparison' is not good enough. I used to think that it is 'to ensure that the independent variable is the only factor causing a change in the reuslts', but I'm not so sure any more. Somebody help? Thanks 

I think your explanation is pretty good. For mine, a control group does serve as a point of comparison so that you can be more confident that your results are truly due to the effect of the IV, and not a confounding variable. I think, perhaps, it might be useful to explicitly state that the control should be, where possible, as similar as it can be to the treatment group and should be exposed to exactly the same conditions as the treatment group, except of course for the IV

[anotherworld2b]

I was wondering for a experiment with the aim to test the effect of exercise on heart rate
What would actually happen to the body as the duration of exercise increases?
Would the heart rate increase/decrease? Why would this happen?

[vox nihili]

I was wondering for a experiment with the aim to test the effect of exercise on heart rate
What would actually happen to the body as the duration of exercise increases?
Would the heart rate increase/decrease? Why would this happen?

Tell us what you think first.