Yacoubb's Bio 3+4 Questions

[Irving4Prez]

The FAQ, just summarises what the Study design tells you..
I'd like to know what points on the study design is misleading...

Reading the above comments, plant growth regulators was a dot point from the study design but discarded from the FAQs.

[Snorlax]

Reading the above comments, plant growth regulators was a dot point from the study design but discarded from the FAQs.

No. If I remember correctly, it states the distinction between different types of growth regulators are not required. This doesn't necessarily mean you don't need to know it.
Also, on top of that statement It even says:
"Signalling molecules, specifically neurotransmitters, animal hormones, pheromones and plant growth hormones, should be distinguished at a functional (rather than a structural) level"

EDIT:
That was straight off the FAQ.
That's also stated on the study design.

[thecreeker]

Another couple of questions guys

1) How does inhibition of acetylcholinesterase cause paralysis? I thought it would just cause muscle spasms due to over stimulation at the post-synaptic membrane?

2) And can someone explain the mechanics behind infertile hybrids? Can they not produce functional gametes? Is it because they have less than the diploid number of chromosomes? I never really understood this and it'd be  good to get this cleared up, even if its like 4 days before the exam haha

Thanks in advance

[slothpomba]

1) How does inhibition of acetylcholinesterase cause paralysis? I thought it would just cause muscle spasms due to over stimulation at the post-synaptic membrane?

Finally a question i'm actually qualified to answer.

It should be obvious from the name that acetylcholinesterase is an enzyme. It's responsible for the breakdown of acetylcholine. If it wasn't broken down, it would just continually hang around and build up (which is what you don't want and this is why our bodies are "designed" to break it down). 

By inhibiting AchE, you inhibit the breakdown of Ach, thus increasing Ach levels. Ach stimulates receptors on muscles causing them to contract. However, in this case, so much Ach is present that the receptors are constantly stimulated, eventually, they develop a tolerance to Ach and cannot be stimulated anymore.

So, in this case, you'd see the person initially twitch a fair bit due to the increased stimulation and then they'd become paralyzed after their receptors become tolerant/desensitised to the effects of Ach.

[Irving4Prez]

No. If I remember correctly, it states the distinction between different types of growth regulators are not required. This doesn't necessarily mean you don't need to know it.
Also, on top of that statement It even says:
"Signalling molecules, specifically neurotransmitters, animal hormones, pheromones and plant growth hormones, should be distinguished at a functional (rather than a structural) level"

EDIT:
That was straight off the FAQ.
That's also stated on the study design.

Well that was based on previous comments, nevertheless another that has been directly extracted from both documents:
"Homeostasis and feedback mechanisms have been deleted from unit 3" - FAQ
"Nature of the stimulus-response model" - Study Design
However, I'm not too sure if they are different topics.

[slothpomba]

Quick shitty diagram i drew for those who are still confused. Just to note, it actually isn't 100% correct but it is "VCE correct" and helps illustrate the concept that you need to understand, namely it increases the levels of Ach (acetylcholine) not by making more but by preventing its breakdown. More Ach present = more receptors stimulated. If you prevent its breakdown, it hangs around in the synapse and receptor for longer continually stimulating it until it just gives up and stops responding. You can get more technical and talk about stuff like depolarization but you dont need to know that for VCE as far as i know.

On the right, you have the normal state where AchE (acetylcholine esterase) inactivates Ach. On the left, you have an absence of AchE (because its blocked and i couldnt be fucked drawing it either) and thus increased Ach levels.

[Snorlax]

Well that was based on previous comments, nevertheless another that has been directly extracted from both documents:
"Homeostasis and feedback mechanisms have been deleted from unit 3" - FAQ
"Nature of the stimulus-response model" - Study Design
However, I'm not too sure if they are different topics.

FAQ:
"Signal transduction can be considered in terms of a stimulus-response model and should be described, in simple terms, as a three-step process: reception (information is received by a cell’s receptor), transduction (information from the receptor is passed on to an effector) and induction/response (various cellular responses are initiated)."

All the FAQ is, is pretty much a summary of the study design..

Now I'm going to stop proving my point..
time to study

[Irving4Prez]

Hey guys, just had a couple of questions regarding the engage exam.

1. Could pain be a result of "inflammation from the non specific response"?

And what would you say for q 32? Answer was B I said C

[Yacoubb]

Hey guys, just had a couple of questions regarding the engage exam.

1. Could pain be a result of "inflammation from the non specific response"?

And what would you say for q 32? Answer was B I said C

One of the symptoms of inflammation is pain surrounding the infective area. An inflammatory response can also be associated with burning sensations near the affected area.

And I would have gone with B because it says it fluctuates around a constant; so this means that frequencies of alleles will eventually always remain in equilibrium, just varying mildly from time to time. But this is highly ambiguous and I think VCAA would be much better in wording!

[Irving4Prez]

One of the symptoms of inflammation is pain surrounding the infective area. An inflammatory response can also be associated with burning sensations near the affected area.

And I would have gone with B because it says it fluctuates around a constant; so this means that frequencies of alleles will eventually always remain in equilibrium, just varying mildly from time to time. But this is highly ambiguous and I think VCAA would be much better in wording!

Thanks Yacoubb, so equilibrium doesn't necessarily mean the allele frequencies are exactly the same in future gens?

[slothpomba]

1. Could pain be a result of "inflammation from the non specific response"?

Yes, non-specific immunity involves the release of histamines, prostaglandins (i think, im no immuno expert) and other pain sensitising substances.

[thecreeker]

Thanks slothpomba, that cleared it up

Also, does anyone know if rational drug design is actually still in the course? I believe the study design says its deleted, but I'm not too sure if this is referring to rational drug design specifically..

[vox nihili]

Thanks slothpomba, that cleared it up

Also, does anyone know if rational drug design is actually still in the course? I believe the study design says its deleted, but I'm not too sure if this is referring to rational drug design specifically..

It shouldn't matter if it is or isn't. Rational drug design is preeeety basic. It's just trying to design drugs to target specific structures, rather than just exposing microbes to a whole heap of random shit and seeing which one kills them!

[Irving4Prez]

Why are Okazaki fragments necessary for the synthesis of a strand complementary to the lagging strand during DNA replication?

[swagsxcboi]

Why are Okazaki fragments necessary for the synthesis of a strand complementary to the lagging strand during DNA replication?

Because the DNA polymerase adds DNA nucleotides to the 3' end. so as DNA helicase unzips the DNA molecule, only a certain part of the strand is exposed for the synthesis of a complementary DNA strand to occur. So the fragments are synthesised instead of a continuing strand (like the leading strand). Thus okazaki fragments form, and ligase must be used to catalyse the formation of the phosphodiester bond in the sugar phosphate backbone between the okazaki fragments.

I don't think we need to know about okazaki fragments though