VCE Biology Question Thread

[vox nihili]

Always receiving conflicting information from sources..

Are they Na+/K+ pumps, ion channels?
Protein carriers or channels?

Some even say depolarisation is ion channels, whist repolarisation is active transport for pump/carriers.

Please end my confusion haha!

Carriers.The pump sets up the concentration gradient.

Depol and repol all have to do with channels, not carriers.

[AllG_]

What's the link between cultural evolution and agriculture?

[Reus]

Primers are bound to the lagging strand which support the synthesis of okazaki fragments (3' to 5') right?

[That Other Guy]

Primers are bound to the lagging strand which support the synthesis of okazaki fragments (3' to 5') right?

A primer is also bound to the leading strand.

[doomdestroyer]

What's the link between cultural evolution and agriculture?

Methods of agriculture are passed on from generation to generation via communication, the methods can even be expanded upon overtime from the current knowledge of agriculture, hence agriculture is an example of cultural evolution.

[Reus]

A primer is also bound to the leading strand.

So both?

[vox nihili]

So both?

You need a primer per fragment because DNA polymerase can't synthesise a new strand from scratch, it can only extend a strand. So the primer provides the bit to extend.

[flares]

Could someone please explain how Paranthropus is related to homogenus?
Thanks

[That Other Guy]

So both?

Yes. However, to be more specific, the primers attach to the leading and lagging template strands, not the leading and lagging strands themselves.

[grannysmith]

-Threshold is reached.
-Consequently sodium channels open causing an influx of Na+ into the axon, thus propagating the impulse causing depolarisation (was initially polarised).
-To correct this, Potassium channels open, allowing for K+ for flow out of the axon, hence repolarising the membrane.

Yeah iffy explanation. Can someone polish this up plz.

Okay, so:
•threshold potential is reached
•depolarisation: sodium channels open resulting in an influx of sodium ions into the neuron
•repolarisation: sodium channels close, potassium channels open causing K+ ions to leave the cell
•adjacent sodium channels are activated, causing the propagation of the action potential along the axon
•sodium/potassium pumps actively transport Na+ out of cell and K+ into cell, thus restoring the resting potential
•impulses are unidirectional due to the refractory period, where sodium channels are temporarily deactivated following depolarisation

How would one go about representing this in a diagram? O.o

[RazzMeTazz]

Would the formation of galls in plants be an example of a chemical defense against pathogens?

[Tyleralp1]

Carriers.The pump sets up the concentration gradient.

Depol and repol all have to do with channels, not carriers.

Wait so when discussing the action potential moving through a neuron, you say the influx of sodium ions and expulsion of potassium ions are due to specific ion channels?

[anat0my]

Would the formation of galls in plants be an example of a chemical defense against pathogens?

No, that would be a physical defence mechanism. The secretion of antibiotic like or such chemicals would be a chemical defence.

[anat0my]

Okay, so:
•threshold potential is reached
•depolarisation: sodium channels open resulting in an influx of sodium ions into the neuron
•repolarisation: sodium channels close, potassium channels open causing K+ ions to leave the cell
•adjacent sodium channels are activated, causing the propagation of the action potential along the axon
•sodium/potassium pumps actively transport Na+ out of cell and K+ into cell, thus restoring the resting potential
•impulses are unidirectional due to the refractory period, where sodium channels are temporarily deactivated following depolarisation

How would one go about representing this in a diagram? O.o

Google image: ?

[vox nihili]

Wait so when discussing the action potential moving through a neuron, you say the influx of sodium ions and expulsion of potassium ions are due to specific ion channels?

The influx of sodium via voltage-gated sodium channels causes depol
The efflux of potassium via voltage-gated potassium channels speeds up repol