VCE Biology Question Thread

[vox nihili]

Do we need to know what ions come in and what go out of the axon during an action potential? Also, so key terms like depolarisation, repolarisation etc are not needed, right?

Also, do we need to know about the myelin sheath, i.e. it's function and location?

It would appear that way. The course has changed since I did it in 2012.

I don't think so, but it doesn't hurt to know. It speeds up action potentials and wraps around the axon. Voilą

[cosine]

It would appear that way. The course has changed since I did it in 2012.

I don't think so, but it doesn't hurt to know. It speeds up action potentials and wraps around the axon. Voilą

What do you mean by this man?

Do all neurones have myelin sheaths?

Also, how do we spell neuron/e? Many books I use spell it neuron and other neurone. Just wondering because in exams, would they take marks off if we misspell a key biology term such as this?
Cheers for the help!

[vox nihili]

What do you mean by this man?

Do all neurones have myelin sheaths?

Also, how do we spell neuron/e? Many books I use spell it neuron and other neurone. Just wondering because in exams, would they take marks off if we misspell a key biology term such as this?
Cheers for the help!

The Q&A appears to suggest that you don't need to know the details of an action potential. They updated the study design in 2013, so whilst it was required knowledge during 2012, it appears (following the Q&A) not to be anymore.

Nope. Short neurones don't have myelin sheathes.

Doesn't matter which way you spell it. In the scientific literature it's referred to as "neuron" but some, including myself, spell it neurone just to be different.

[vox nihili]

What do you mean by this man?

Do all neurones have myelin sheaths?

Also, how do we spell neuron/e? Many books I use spell it neuron and other neurone. Just wondering because in exams, would they take marks off if we misspell a key biology term such as this?
Cheers for the help!

Here's an article that explains the difference if you're interested: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2347883/?page=1

[TheAspiringDoc]

Hi,
Could someone please expplain to me the concept of how a cell normally receives nutrients?
Thanks 

[cosine]

Do we need to know what ions come in and what go out of the axon during an action potential? Also, so key terms like depolarisation, repolarisation etc are not needed, right?

[sunshine98]

Do we need to know what ions come in and what go out of the axon during an action potential? Also, so key terms like depolarisation, repolarisation etc are not needed, right?

Yep and yep. 

Also I have a  q - the FAQ says we need to be able to ''identify'' biomacromolecule , this means we do not need to know how to draw  the structure ,  right?   
thanks

[Sine]

What do we need to know about stem cells?

Do we need to know the difference between Embryonic and Adult Stem cells?

Do we need to know the terms Totpotent/Multipotent/Pluripotent?

[cosine]

Yep and yep. 

Also I have a  q - the FAQ says we need to be able to ''identify'' biomacromolecule , this means we do not need to know how to draw  the structure ,  right?   
thanks

Cheers sunshine98

Do Na+ ions come out and K+ ions go in the neurone? Also, is it a 3:2 ratio? Cheers.

[BakedDwarf]

What do we need to know about stem cells?

Do we need to know the difference between Embryonic and Adult Stem cells?

Do we need to know the terms Totpotent/Multipotent/Pluripotent?

What do we need to know about stem cells?
Briefly what they are and their applications to evolution

Do we need to know the difference between Embryonic and Adult Stem cells?
Not too sure, but knowing that embryonic stem cells can differentiate into most cells and adult stem cells to certain wouldn't hurt. I think it is also good to know their applications, such as growing tissue in the laboratory to replace damaged ones

Do we need to know the terms Totpotent/Multipotent/Pluripotent?
Don't think so.

Cheers sunshine98

Do Na+ ions come out and K+ ions go in the neurone? Also, is it a 3:2 ratio? Cheers.

3 sodium ions are actively pumped out and 2 potassium ions are actively pumped in (yes, 3:2 ratio)

[vox nihili]

Use the study design as a guide to work out what you need to know. If it's not clear, look at the FAQs. If you're not sure, then learn it.

You're all probably spending too much time wondering whether you need to know something, when you could probably better spending that time just learning it anyway

[cosine]

What do we need to know about stem cells?
Briefly what they are and their applications to evolution

Do we need to know the difference between Embryonic and Adult Stem cells?
Not too sure, but knowing that embryonic stem cells can differentiate into most cells and adult stem cells to certain wouldn't hurt. I think it is also good to know their applications, such as growing tissue in the laboratory to replace damaged ones

Do we need to know the terms Totpotent/Multipotent/Pluripotent?
Don't think so.

3 sodium ions are actively pumped out and 2 potassium ions are actively pumped in (yes, 3:2 ratio)

Are they actively pumped out, or do they diffuse out/in (facilitated), as when the action potential propagates along the axon, the membrane depolarises and the ions rush out along the concentration gradient?

[BakedDwarf]

Are they actively pumped out, or do they diffuse out/in (facilitated), as when the action potential propagates along the axon, the membrane depolarises and the ions rush out along the concentration gradient?

During resting potential, sodium ions are actively pumped out because they are going against a concentration gradient. However, during action potential, the membrane becomes permeable for sodium ions, which allow the sodium ions to rapidly diffuse into the neurone.

Now for my question, what plant defences (both physical and chemical) are we required to know for the exam? If a question asked to list a few physical and chemical plant defences, what could you say?

[cosine]

Need help with the meaning of fossilisation and index fossils.

Also, can someone explain the connection between Eras, Epochs and Periods. Cheers

[heids]

Need help with the meaning of fossilisation and index fossils.

Also, can someone explain the connection between Eras, Epochs and Periods. Cheers

Google them.  I'm happy to help, but your first step is to try out Wikipedia.  All the info is there, easily accessible.  Then ask when you get stuck and can't find something from that.