VCE Biology Question Thread

[FatimaEl]

Thanks FatimaEl, so signal transduction can occur outside of cells?

Not the entire process, but just the reception stage. Because Neurotransmitters are protiens, and im sure you know by now that protiens do not bind within the cytosol of a cell, but rather on the surface

[The Usual Student]

Ok thanks, but I saw another paper saying that light independent occurs in both light and dark, so I'm not sure which oneis right

Thanks FatimaEl, so signal transduction can occur outside of cells?

it is a grey area,
You could argue it does since maybe the products from light dependent wait 12 hours ( so it's night )then undergo light independent? I reckon it is is safer to go with day since the textbook emphasises how the tow are linked and going with day demonstrates that knowledge.
Can anyone clarify on this? It should theoretically work in night and day shouldn't it?or does it occur immediately after light dependent ?


Also, can someone tell me why we have both FADH2 and NADH? Why do we need tow types of carrier molecules? does it give us an advantage?

[Calebark]

Also, can someone please explain why I got these multiple choices wrong clearly?

Sweetcheeks covered #1 and #2, so I won't go through those.

Well, as it says right there, pheromones are species specific, I can't really elaborate further. You could go through process of elimination, however. A is incorrect, as it's from animals and insects only. B would be incorrect, as we've been taught nothing to contradict this. C gives you no information to suggest this, perhaps it has different uses. Thus D.

I was taught that the Calvin-Benson Cycle can only occur in the daytime, however I do not know why. Perhaps someone who is better at plants can help out here.

There wouldn't be chloroplasts in onion root cells as root cells do not see sunlight.

[FatimaEl]

it is a grey area,
You could argue it does since maybe the products from light dependent wait 12 hours ( so it's night )then undergo light independent? I reckon it is is safer to go with day since the textbook emphasises how the tow are linked and going with day demonstrates that knowledge.
Can anyone clarify on this? It should theoretically work in night and day shouldn't it?or does it occur immediately after light dependent ?

It does not work at night, the term "independent" just refers to how light isnt a direct input in the reaction, but since it is a part of photosynthesis, it cannot occur at night as photosynthesis only occurs in the morning. This is from what ive been taught, maybe it does occur in the night? but im pretty certain that its wrong to simply say "light dependent occurs in the morning, while light independent occurs at night" as a comparison, cause light independent definitely can work in the morning.

Also, can someone tell me why we have both FADH2 and NADH? Why do we need tow types of carrier molecules? does it give us an advantage?

From what i know, FADH2 carries twice as much hydrogen, so that would be an advantage i suppose. Not sure why else we'd need two types.

[The Usual Student]

It does not work at night, the term "independent" just refers to how light isnt a direct input in the reaction, but since it is a part of photosynthesis, it cannot occur at night as photosynthesis only occurs in the morning. This is from what ive been taught, maybe it does occur in the night? but im pretty certain that its wrong to simply say "light dependent occurs in the morning, while light independent occurs at night" as a comparison, cause light independent definitely can work in the morning.

From what i know, FADH2 carries twice as much hydrogen, so that would be an advantage i suppose. Not sure why else we'd need two types.

Yeah I checked the connect notes, Light  independent can ostensibly work both at night and day. Not too sure what VCAA wants though.

[FatimaEl]

Yeah I checked the connect notes, Light  independent can ostensibly work both at night and day. Not too sure what VCAA wants though.

yes exactly, one would presume so cause photosynthesis is a long process and could end up going into the night, which wouldnt be a problem for the light independent stage, as long as its got its inputs

[Hayley_turnham]

is Australopithecus considered a great ape and/or hominin?

[FatimaEl]

is Australopithecus considered a great ape and/or hominin?

Hominin 
From the study design> "major trends in hominin evolution from the genus Australopithecus to the genus Homo"

[plsbegentle]

is Australopithecus considered a great ape and/or hominin?

god bless u

[Hayley_turnham]

god bless u

??

[anniebrejcha]

hi guys!!
for what reasons would a perfectly healthy cell "apoptose"?

[The Usual Student]

hi guys!!
for what reasons would a perfectly healthy cell "apoptose"?

two main categories of reasons
- unnecessary: Some cells may not serve a purpose and hence are waste of resources, hence, they undergo apoptosis ( In the human fetus, cells are killed in order to create the webbing in between the toes on your feet )
- damaged: For example when a cell is infected by a virus it can undergo apoptosis in order to ensure the virus does not infect more cells.

[anniebrejcha]

two main categories of reasons
- unnecessary: Some cells may not serve a purpose and hence are waste of resources, hence, they undergo apoptosis ( In the human fetus, cells are killed in order to create the webbing in between the toes on your feet )
- damaged: For example when a cell is infected by a virus it can undergo apoptosis in order to ensure the virus does not infect more cells.

thanks very much!!
sorry for posting the question twice.

[gameboy99]

Is this photosynthesis equation right?

6CO2 + 12H20 -------> C6H1206 + 6CO2 + 6H20

*light energy and chlorophyll on either side of arrow

[The Usual Student]

Is this photosynthesis equation right?

6CO2 + 12H20 -------> C6H1206 + 6CO2 + 6H20

*light energy and chlorophyll on either side of arrow

I think so but Idk what the official VCAA equation would be, I usually dont write the 6 H2O instead I write the other H2O just as 6H2O.