VCE Biology Question Thread

[Chocolatepistachio]

for this question why is the pgh part in pa  and then you convert it back to kpa

[Billuminati]

for this question why is the pgh part in pa  and then you convert it back to kpa

The units for rho g h (hydrostatic pressure) multiply to give N/m^2, which is equivalent to Pa. You can't add apples and oranges so you need to convert Pa to kPa so that they're in the same units before you can add them

[Chocolatepistachio]

why does the answer have to be in kpa though arent the units for pressure pascals

[Billuminati]

why does the answer have to be in kpa though arent the units for pressure pascals

Although the SI units are Pa, it's often easier to write the units as kPa cuz u don't have to write as many 0s

[Chocolatepistachio]

Oh ok so then it wouldn’t really matter if you used pa or Kpa both would be correct

[Chocolatepistachio]

What event must occur in the postsynaptic neuron before it generates an action potential?
A the postsynaptic neuron must release neurotransmitters to generate an action potential.
B the postsynaptic neuron membrane must depolarise and reach a threshold potential before it is able to generate an action potential
C the postsynaptic neuron membrane must hyperpolarise  to generate an action potential
D the postsynaptic cell must fuse to the postsynaptic cell membrane to generate an action potential

Would this be b

[Billuminati]

What event must occur in the postsynaptic neuron before it generates an action potential?
A the postsynaptic neuron must release neurotransmitters to generate an action potential.
B the postsynaptic neuron membrane must depolarise and reach a threshold potential before it is able to generate an action potential
C the postsynaptic neuron membrane must hyperpolarise  to generate an action potential
D the postsynaptic cell must fuse to the postsynaptic cell membrane to generate an action potential

Would this be b

Yes the units don't matter as long as they're consistent, and yes it's B. Resting membrane potential is -70mV and the threshold for AP generation is usually around -55mV

[biology1234]

What is internal fertilization?

[Sine]

What is internal fertilization?

internal vs external fertilization depends on the location of the joining of the sperm and egg. Internal fertilization is when this fusion occurs inside the body (e.g. humans), external fertilization is when the fusion occurs in the environment outside of the body (e.g. frogs)

[Chocolatepistachio]

Adrenalin activates the cyclic AMP pathway in liver cells. In this example adrenalin(hormone) is a (n) ——-and cAMP is a (n)——-
A ligand;receptor
B first messenger; hydrophobic hormone
C second messenger; first messenger
D first messenger; second messenger

Would this be d

[Billuminati]

Adrenalin activates the cyclic AMP pathway in liver cells. In this example adrenalin(hormone) is a (n) ——-and cAMP is a (n)——-
A ligand;receptor
B first messenger; hydrophobic hormone
C second messenger; first messenger
D first messenger; second messenger

Would this be d

I would've said ligand and 2nd messenger respectively, but 1st messenger is fine too

[Chocolatepistachio]

Why does intrapulmonary pressure equalise with atmospheric pressure but intrapleural pressure does not equalise with atmospheric pressure

[Billuminati]

Why does intrapulmonary pressure equalise with atmospheric pressure but intrapleural pressure does not equalise with atmospheric pressure

If your intrapleural pressure equilibriates with the atmosphere pressure, your lungs will actually collapse because the negative intrapleural pressure helps keep them inflated and counters their tendency to recoil elastically ie shrink. Note that this isn't assessable until 2nd year uni physiology

[Olisadxbe]

Hey people, i was just wondering if anyone has a time line on life on earth for unit 4 AOS 1 biology, if you do that would be amazing

[MEH0010]

Hey people, i was just wondering if anyone has a time line on life on earth for unit 4 AOS 1 biology, if you do that would be amazing

Hey.
On the VCAA 2018 exam (multiple choice question 27) is a summarised timeline of life on earth. If I was you, I would print that out and annotate it as it is what VCAA wants you to know.
Hope this helps.