General Thoughts: Biology (4 Viewers)

[Cataclysm]

Yeah, I think that stimulus was stupid. The abortion thing first came to mind, but then it made me think - why would you abort the baby just because it has the 'risk' of getting breast cancer? Doesn't really make sense. People abort now because they know their child is going to develop down syndrome, etc, but with breast-cancer it's just a risk.

Wait what? Didn't the stimulus say that the foetus was screened to not contain the genome for hereditary breast cancer?

If not... Then that's a few marks gone FFS!!!

 

[lolrofllol]

I think question 11 is D because D shows a gradual slope (smallest during midday, largest during midnight). In B, the stomata are small at mightnight, which doesn't make much sense.

But when can they photosynthesise if the stomates are closed all day? They will die if they can't photosynthesise (Stomates are less than half open for the WHOLE day in D)

 

[Bunzhou]

Yeah maybe they do want to die, they figured it was too dry so they'd kill themselves haha

But when can they photosynthesise if the stomates are closed all day? They will die if they can't photosynthesise (Stomates are less than half open for the WHOLE day in D)

 

[Currlz]

I found it quite easy, trickiest part was the multiple choice.

 

[Ethanescence]

Wait what? Didn't the stimulus say that the foetus was screened to not contain the genome for hereditary breast cancer?

If not... Then that's a few marks gone FFS!!!

Yeah, it said the embryo was screened. But 'screening' only tests for the presence of the gene. So if it was 'screened' to show the gene, it would need to be aborted to remove that gene from the population.

I don't know, that question confused me.

 

[akim93]

exam was quite good except for the communication part with question on not generation action potentia stimuli shit

isn't q 11 A??

Because when plants are exposed to the sunlight they open up their stomata size to transpire more water??

 

[christoffpow]

What's your reasoning?

Graph D shows more gradual closing and opening of stomata in correlation with time.. Both B and D are technically correct. Graph D more likely. But hey, could be wrong

 

[Liyo]

Re: Hsc 2009 bio exam

Overall the exam was okay. (haha...i don't want to say anything to jinx my results )
I'm glad there wasn't anything on transpiration/translocation ><!

 

[Bunzhou]

No because its "dry" remember, if it opens up it will transpire at the speed of light and therefore die. It doesn't want to transpire more water -_- it uses water for photosynthesis. It wants to close it so that it keeps cool and theres is less water loss during the hottest part of the day.

exam was quite good except for the communication part with question on not generation action potentia stimuli shit

isn't q 11 A??

Because when plants are exposed to the sunlight they open up their stomata size to transpire more water??

 

[Ethanescence]

But when can they photosynthesise if the stomates are closed all day? They will die if they can't photosynthesise (Stomates are less than half open for the WHOLE day in D)

That's a good point... I think you're right.

I guess the stomata basically close at night because they don't photosynthesis. When I did the question, I looked at it only from the perspective of transpiration, not photosynthesis.

 

[Currlz]

exam was quite good except for the communication part with question on not generation action potentia stimuli shit

isn't q 11 A??

Because when plants are exposed to the sunlight they open up their stomata size to transpire more water??

I studied up on action potentials and I think communication section was good, I put the minima style parabola shaped graph for the stomates.

 

[greatgreeks2]

That's a good point... I think you're right.

I guess the stomata basically close at night because they don't photosynthesis. When I did the question, I looked at it only from the perspective of transpiration, not photosynthesis.

yeah i was told the answer for q 11 was a by nearly every one at my school

 

[akim93]

I studied up on action potentials and I think communication section was good, I put the minima style parabola shaped graph for the stomates.

for that question
i talked about repolorisation and depolorisation
am i right??

 

[lolrofllol]

for that question
i talked about repolorisation and depolorisation
am i right??

Fk I forgot to talk about the technical side of action potentials... only wrote about why not all should generate a stimuli (not all stimuli are significant enough, brain will be overwhelmed etc.) I KNEW I HAD SOMETHING MISSING

 

[Currlz]

for that question
i talked about repolorisation and depolorisation
am i right??

Yes I also mentionedd

Neurone fires it is known as the 'all or none' response

excitation that causes the neurone to fire is called the threshold of reaction.

In the polorisation I mentioned the potassium and sodium ions and shit.

I wrote a fair bit of it then did less for the big last question ahah.

 

[lil_fadgey]

i thought it was pretty easy. i finished with an hour and a half to go and left, went and saw my teacher and went over it, got 14 outa 15 for the multiple choice, and didnt do to bad in the rest. The option on communication was easy except for that fucked up 5 marker on why there was no action potential, i could of answered that in once sentence lol.

over all, fairly easy, bring on chemistry

 

[greatgreeks2]

some one tell me what the correct ans for q 4 and 11 are

lets have a poll

 

[Ethanescence]

For the action potential one, ended up drawing a diagram to show failed action potentials and the threshold, and describing sodium/potassium channels for depolarisation/repolarisation.

 

[Currlz]

I fucked up a basic thing and put thrush as a bacteria thing, thats the main mistake I can think of..silly.

 

[Ethanescence]

some one tell me what the correct ans for q 4 and 11 are

lets have a poll

Question 4 is definitely A. Question 11 is B, even though I answered D.