VCE Biology Question Thread

[darkz]

Hey guys,

Are we supposed to know specific pathogens for the VCE Biology course? Which pathogens should we know and what level of understanding should we have?

Thanks

Well you should know about the different categories of pathogens - you don't need to know specific examples of ones. You should also have a pretty good understanding about bacteria and viruses, as for prions, fungi, protists, worms etc, you just need to know what they are briefly

[TheBigC]

Well you should know about the different categories of pathogens - you don't need to know specific examples of ones. You should also have a pretty good understanding about bacteria and viruses, as for prions, fungi, protists, worms etc, you just need to know what they are briefly

I can corroborate this. Of all the exams I have done (1997-2017), the questions regarding different pathogens and their specifics involve either viruses or bacteria (more often viruses). I have, however, seen a few multi-choices involving prions (i.e. in the context of protein denaturation). All-in-all, you should be familiar with the general structure of viruses (capsid/ protein coat, RNA/ DNA/ double/ singe-stranded nucleic acids, as well as modes of controlling aspects of cell function: be sure to be familiar with antiviral drug functions too) and bacteria (shapes and function of antibiotics on their systems). I must admit, though, that general adaptations espoused by many pathogens has been discussed in exams that exceeds one's account of viruses and bacteria, for example, I did a question in a past VCAA exam specifying particular characteristics of a parasitic pathogen X that binds to the intestinal tract of animals such as humans. It required that you identified that the pathogen potentially has suction characteristics to enable for it to stick to the intestinal tract... (a diagram was also included). Hence, you must watch out for these as well.

EDIT: Be sure to understand viruses in the context of HIV, too. (This is a very important dot point on the study design)

[TheBigC]

Then what would increasing the IV range improve if not accuracy or precision? Could it be validity, because we are able to ensure that the results reflect on the concept being tested over a wider IV range?

Validity is the extent to which an experiment measures the concept being test

Increasing the range of data points improves validity (you are correct), as well as reliability of results.

[Monkeymafia]

Is there a reason why neutrophils go to new wounds whilst macropages go to old wounds?

Does it have something to do with the presence of granules in neutrophils?

[darkz]

Is there a reason why neutrophils go to new wounds whilst macropages go to old wounds?

Does it have something to do with the presence of granules in neutrophils?

I don't think its right to think of macrophages as only going to "old" wounds and neutrophils only to "new" wounds - as I'm pretty sure they are both present at less recent wounds, only that there may more more macrophages than neutrophils. This is because neutrophils circulate around in the blood, and therefore if you get a cut or something, the capillaries are damaged and the neutrophils migrate to the site very quickly - so they are present at "new" recent wounds. (Capiliaries dilate so neutrophils can exit and go into the tissue). While macrophages just take longer to migrate to the area of infection etc - so they are present at less recent or "older" wounds.

Edit: fixed wording

[vox nihili]

Is there a reason why neutrophils go to new wounds whilst macropages go to old wounds?

Does it have something to do with the presence of granules in neutrophils?

I think darkdzn has probably given you an answer that is suitable to VCE. It's not really useful to think of this distinction. Macrophages and neutrophils do both work together to get rid of bacteria.

I see where your question is coming from, but the answer to it is well and truly beyond VCE. Basically it just has to do with their roles. Neutrophils are designed to come in and gobble up bacteria; whereas macrophages are designed to clear out wounds and get remodelling happening. None of this is relevant to VCE though so I wouldn't worry about it

[PopcornTime]

Does auxin cause the pumping of H+ ions into the cell wall to loosen cellulose fibres or the production growth proteins? Or is this just an example of one signalling molecule causing different cellular responses?

 

[darkz]

Does auxin cause the pumping of H+ ions into the cell wall to loosen cellulose fibres or the production growth proteins? Or is this just an example of one signalling molecule causing different cellular responses?

Well auxin does not refer to a single hormone, it refers to a group of plant hormones which carry out a variety of different responses. For example, types of auxin include Indole Acetic acid, Indole Butyric acid etc. So yes, I think that it is an example of a signalling molecule which can cause different cellular responses.

[PopcornTime]

Well auxin does not refer to a single hormone, it refers to a group of plant hormones which carry out a variety of different responses. For example, types of auxin include Indole Acetic acid, Indole Butyric acid etc. So yes, I think that it is an example of a signalling molecule which can cause different cellular responses.

Does this mean that different types of auxin could be hydrophilic or hydrophobic, which would explain the production of growth hormones (by binding of auxin to intracellular receptor in nucleus)?

[darkz]

Does this mean that different types of auxin could be hydrophilic or hydrophobic, which would explain the production of growth hormones (by binding of auxin to intracellular receptor in nucleus)?

Yes, there are certain auxins which are hydrophobic or hydrophobic.

[PopcornTime]

Can someone confirm the following conditions for long-day plants flowering?
- long day, short night: flowering
- long day, interrupted short night: flowering
- interrupted long day (by brief dark periods), short night: flowering

What if a long day plant was subjected to interrupted long day and interrupted short night?

[MAGGOT]

What type of cells go under clonal expansion?

[PhoenixxFire]

What type of cells go under clonal expansion?

B & T cells

[MAGGOT]

Are blood group or blood related case studies important?

[PhoenixxFire]

Are blood group or blood related case studies important?

Not anymore - it was on the previous study design