VCE Biology Question Thread

[solution]

What is the result of translation? Is it a primary protein, polypeptide, polypeptide chain or a protein?

[The Usual Student]

What is the result of translation? Is it a primary protein, polypeptide, polypeptide chain or a protein?

I believe all four of those terms work

[vox nihili]

What is the result of translation? Is it a primary protein, polypeptide, polypeptide chain or a protein?

Anything but primary protein. (beyond VCE but proteins start to fold before they're completely built)

[solution]

Anything but primary protein. (beyond VCE but proteins start to fold before they're completely built)

Guess these NEAP worked solutions are incorrect... 

[blacksanta62]

1. You could probably try this one out first.
Yep

2. Again, what do you think? This isn't a question that requires a definition. I'd really try to stick away from remembering definitions. You'd do much better to remember concepts instead.
That's a good point, wouldn't really be asked to define it would I...

3. Autoradiography does usually involve gel electrophoresis, but I don't think that's an acceptable question for VCE level, so I wouldn't worry about it. Be more specific about the molecular level with probes and then that answer should come together nicely (e.g. you should speak about the complementary binding of the probe to its target sequence). I'd also probably tighten up the "labelled" part of the answer; because it seems to suggest that you don't really know what that means (which may or may not be the case, it just looks like that!)
How could I tighten that up? I really don't know how else to put it unless I name the specific examples of labels. 

Edit:
1) If asked to explain the role of Taq polymerase are we allowed to refer to either strand as leading or lagging? Or should I reserve those words for DNA replication only?
2) Is this a suitable definition for a gene probe: A short sequence of DNA which is complementary to our target sequence of DNA. The probe is labelled with radioactive or fluorescent dye and anneals itself to the target sequence, allowing us to find the target DNA fragment.

Thank you

[vox nihili]

Edit:
1) If asked to explain the role of Taq polymerase are we allowed to refer to either strand as leading or lagging? Or should I reserve those words for DNA replication only?
2) Is this a suitable definition for a gene probe: A short sequence of DNA which is complementary to our target sequence of DNA. The probe is labelled with radioactive or fluorescent dye and anneals itself to the target sequence, allowing us to find the target DNA fragment.

Thank you

1. Is there a leading and a lagging strand in PCR? You tell me

2. Yep, only thing to change is to say that the probe is a nucleic acid (so either DNA or RNA).

[blacksanta62]

Here's how I saw it (I've already completed the SAC before posting this question so I'll learn from my mistakes if it's not in PCR):
PCR is a form of DNA replication but it's not in the nucleus. Normal DNA replication involves DNA polymerase which can only read in the 3'-5' direction and add complementary nucleotides in the 5'-3' (the primer which is put down by primase, hope my explanation is making sense). This is the leading strand. The other (5'-3') is the lagging strand.

The reason why I think it might not be true: In DNA replication, there is a replication fork, specific sequences of DNA which are unwound. In PCR, the two strands completely dissociate from on another due to the high temperatures. Therefore, no leading and lagging strand.

[vox nihili]

Here's how I saw it (I've already completed the SAC before posting this question so I'll learn from my mistakes if it's not in PCR):
PCR is a form of DNA replication but it's not in the nucleus. Normal DNA replication involves DNA polymerase which can only read in the 3'-5' direction and add complementary nucleotides in the 5'-3' (the primer which is put down by primase, hope my explanation is making sense). This is the leading strand. The other (5'-3') is the lagging strand.

The reason why I think it might not be true: In DNA replication, there is a replication fork, specific sequences of DNA which are unwound. In PCR, the two strands completely dissociate from on another due to the high temperatures. Therefore, no leading and lagging strand.

Smashed it

[gameboy99]

Hi guys,
I have been looking through hundreds of diagrams of the full meiosis process. Could someone go through some of my pics of meiosis that I have attached which I could draw and get full marks on the end of year exam.
Thanks 

[vox nihili]

Hi guys,
I have been looking through hundreds of diagrams of the full meiosis process. Could someone go through some of my pics of meiosis that I have attached which I could draw and get full marks on the end of year exam.
Thanks 

How about you tell us what you know first and then we can help you fix it up?

[gameboy99]

I understand the process of meiosis but what I am having trouble is clearly show the processes of independent assortment and crossing over and recombination.
Independent assortment occurs at anaphase I but is set up in metaphase I and is the orientation of homologous pairs to each pole which is random/independent. While crossing over and recombination occurs at prophase I. Crossing over is the physical exchange between chromosome segments of non-sister chromatids creating s recombinant chromosome. 

Another question is that (for the end of year exam) is better to show the maternal and paternal chromosomes in red and blue.

[plsbegentle]

I understand the process of meiosis but what I am having trouble is clearly show the processes of independent assortment and crossing over and recombination.
Independent assortment occurs at anaphase I but is set up in metaphase I and is the orientation of homologous pairs to each pole which is random/independent. While crossing over and recombination occurs at prophase I. Crossing over is the physical exchange between chromosome segments of non-sister chromatids creating s recombinant chromosome. 

Another question is that (for the end of year exam) is better to show the maternal and paternal chromosomes in red and blue.

You answered your own question, Well Done!

For the exam, it really doesn't matter, Just make sure the examiners can understand what you are trying to say.

[gameboy99]

You answered your own question, Well Done!

For the exam, it really doesn't matter, Just make sure the examiners can understand what you are trying to say.

Yay
But can someone pick the best meiosis diagram just in case to draw for like a sac or the end of year exam if they asked to "Draw the whole process of meosis".
Thanks

[blacksanta62]

Smashed it

So which is correct?

[vox nihili]

So which is correct?

Dude, trust yourself a bit more.

Your reasoning was perfect, that's why you smashed it. If you can reason that there's no lagging/leading strand like that, why do you need someone to tell you there's no lagging/leading strand in PCR? You nailed it!