VCE Biology Question Thread

[Billuminati]

Nuclear pores permit the passage of all the following except:
A proteins: into and out of the nucleus
B RNA: only to the outside of the nucleus
C DNA: into and out of the nucleus
D enzymes: into and out of the nucleus


Would this be c

Yes, DNA never leaves the nucleus, you can only find cytoplasmic DNA in the chloroplast or mitochondria as they're of bacterial origin

[Chocolatepistachio]

ok thanks
why would d be wrong for this question
 wouldn't it be d because glucose is moving from b to a then there will be high water in b

[Billuminati]

ok thanks
why would d be wrong for this question
 wouldn't it be d because glucose is moving from b to a then there will be high water in b

Yes it's D. If it's marked wrong then the solutions have a typo. At equilibrium you'll have both sides with 1.5M glucose, but there's still a difference in osmolarity (solute concentration) as sucrose can't cross the membrane. Water diffuses by osmosis from an area of low solute concentration to high solute concentration so it will move from B to A

[Chocolatepistachio]

How does a gustatory cell transduce a chemical taste into an action potential can someone explain

[Billuminati]

How does a gustatory cell transduce a chemical taste into an action potential can someone explain

We weren't taught how even in 2nd year biomed anatomy, we're just told that they interpret different tastes as action potentials and send that info through to the gustatory cortex in the insular lobe via CNVII (facial nerve) and CNIX (glossopharyngeal nerve) depending on the location of the taste bud. The facial nerve is responsible for the anterior 2/3 of the tongue whereas the glossopharyngeal nerve takes the posterior 1/3

[-Lilac-]

How does a gustatory cell transduce a chemical taste into an action potential can someone explain

Billuminati is correct, this is way out of VCE knowledge. However, I can give you an example of how this works.

Gustatory cells themselves contain many membrane receptors. An example of a receptor that may be present is TRPV1. This receptor, among other things, can recognize a  compound called Capsaicin. This leads to the activation of the TRPV1, which is an ion channel, that then opens allowing the influx of Ca2+ ions into the cell. This leads to depolarization (the membrane potential becomes more positive) and the AP threshold is reached. An action potential is then fired.

[Bri MT]

My genetics knowledge is very bad so please take this with a grain of salt, but I'm pretty sure true breeding individuals must be homozygotes

Yes, a heterozygote cross results in 3:1 dominant:recessive expression in the offspring
i.e. heterozygotes are not true breeding, as not all offspring express the parents' phenotype.

[Chocolatepistachio]

The transfer of a phosphate group from the phosphoenolpyruvate to ADP is classified as:
A oxidative phosphorylation
B first phosphorylation
C second phosphorylation
D substrate level phosphorylation

Would this be d

[Billuminati]

The transfer of a phosphate group from the phosphoenolpyruvate to ADP is classified as:
A oxidative phosphorylation
B first phosphorylation
C second phosphorylation
D substrate level phosphorylation

Would this be d

Yes it is, although you’re only supposed to see this 1st year biomed biochem, not VCE.

[Chocolatepistachio]

If someone could help with this question can someone explain

Which is not an example of a graded potential?
A a receptor potential in a sensory receptor cell
B a depolarising excitatory postsynaptic potential (EPSP)
C a hyperpolarising inhibitory postsynaptic potential(IPSP)
D resting membrane potential on receptive (distal) region of sensory neurons

[Billuminati]

If someone could help with this question can someone explain

Which is not an example of a graded potential?
A a receptor potential in a sensory receptor cell
B a depolarising excitatory postsynaptic potential (EPSP)
C a hyperpolarising inhibitory postsynaptic potential(IPSP)
D resting membrane potential on receptive (distal) region of sensory neurons

From 1st year biomed neurobio, the first 3 are all graded so the answer is D. I think this question is more of a VCE psych board question (not that psych is a real science).

[-Lilac-]

If someone could help with this question can someone explain

Which is not an example of a graded potential?
A a receptor potential in a sensory receptor cell
B a depolarising excitatory postsynaptic potential (EPSP)
C a hyperpolarising inhibitory postsynaptic potential(IPSP)
D resting membrane potential on receptive (distal) region of sensory neurons

Just to add onto Billuminati’s response, put simply, a graded potential is any change in membrane potential (from resting) that is not an action potential.

[Chocolatepistachio]

would this be c or would it only affect primary and secondary

[Billuminati]

would this be c or would it only affect primary and secondary

I think it would be primary and secondary because it doesn't mention how many subunits ie separate polypeptide chains make up the CFTR channel

[Chocolatepistachio]

would this be a