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November 01, 2024, 10:26:35 am

Author Topic: VCE Biology Question Thread  (Read 3889137 times)  Share 

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vox nihili

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Re: VCE Biology Question Thread
« Reply #6840 on: October 29, 2015, 11:24:42 am »
+1
What is the difference between "Transformed" and "transfected" ?

It's supposed to be that transformation involves bacteria and transfection involves eukaryotic cells, though in reality nobody adheres to this distinction. Both are normally used interchangeably.
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Elizawei

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Re: VCE Biology Question Thread
« Reply #6841 on: October 29, 2015, 11:31:44 am »
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Thanks! Also, what is a good definition for "Okazaki fragments"?
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vox nihili

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Re: VCE Biology Question Thread
« Reply #6842 on: October 29, 2015, 11:35:12 am »
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Thanks! Also, what is a good definition for "Okazaki fragments"?

You won't be asked to define Okazaki fragments, just explain how/why they're generated
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Elizawei

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Re: VCE Biology Question Thread
« Reply #6843 on: October 29, 2015, 11:38:09 am »
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Ah ok thank you so much!!!!  ;D
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cosine

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Re: VCE Biology Question Thread
« Reply #6844 on: October 29, 2015, 11:42:36 am »
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Guys whats a good thing to do today? Should I go over my weaknesses (linked genes, definitions, human evolution, gene technology) or should I do some practice exams? Or both, and after i try to solidify my weaknesses tackle some exams?
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Biology24123

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Re: VCE Biology Question Thread
« Reply #6845 on: October 29, 2015, 11:52:23 am »
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Guys whats a good thing to do today? Should I go over my weaknesses (linked genes, definitions, human evolution, gene technology) or should I do some practice exams? Or both, and after i try to solidify my weaknesses tackle some exams?

Go through examiners reports

BakedDwarf

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Re: VCE Biology Question Thread
« Reply #6846 on: October 29, 2015, 11:52:32 am »
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You won't be asked to define Okazaki fragments, just explain how/why they're generated

Can someone please explain how/why they're generated?

cosine

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Re: VCE Biology Question Thread
« Reply #6847 on: October 29, 2015, 12:02:22 pm »
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Can someone please explain how/why they're generated?

You have a double stranded DNA molecule. One end is the 5' end, and the antiparallel end is the 3' end. So DNA helicase moves along the DNA helix and simultaneously unwinds the DNA, whilst this is happening, RNA polymerase synthesises primers on both DNA template strands. When the primers are added onto the DNA templates, we know that DNA polymerase can attach to them and begin synthesising the daughter strands. DNA polymerase only works in the 5'-3' direction, so it only synthesises DNA in the 5 prime to 3 prime direction. As DNA helicase moves along the DNA, one of the template strands also runs in the direction of the helicase in the 3'-5' direction, so this will be continuously synthesised. However, as the antiparallel orientation of DNA, the opposite strand will run in the 5'-3' direction, so as DNA helicase unwinds the DNA helix, the 3' ends keep getting exposed as it moves along. So as they keep getting exposed, new primers are attached to those sections and DNA polymerase starts to synthesise the daughter strand (lagging strand) creating fragments, known as Okazaki fragments. These fragments are then bonded together via DNA ligase, which forms phosphodiester bonds between the backbones of the fragments.
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BakedDwarf

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Re: VCE Biology Question Thread
« Reply #6848 on: October 29, 2015, 12:25:11 pm »
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You have a double stranded DNA molecule. One end is the 5' end, and the antiparallel end is the 3' end. So DNA helicase moves along the DNA helix and simultaneously unwinds the DNA, whilst this is happening, RNA polymerase synthesises primers on both DNA template strands. When the primers are added onto the DNA templates, we know that DNA polymerase can attach to them and begin synthesising the daughter strands. DNA polymerase only works in the 5'-3' direction, so it only synthesises DNA in the 5 prime to 3 prime direction. As DNA helicase moves along the DNA, one of the template strands also runs in the direction of the helicase in the 3'-5' direction, so this will be continuously synthesised. However, as the antiparallel orientation of DNA, the opposite strand will run in the 5'-3' direction, so as DNA helicase unwinds the DNA helix, the 3' ends keep getting exposed as it moves along. So as they keep getting exposed, new primers are attached to those sections and DNA polymerase starts to synthesise the daughter strand (lagging strand) creating fragments, known as Okazaki fragments. These fragments are then bonded together via DNA ligase, which forms phosphodiester bonds between the backbones of the fragments.

Thanks!

So where would you add the formation of Okazaki fragments in the process of DNA replication below?

1. DNA helicase unwinds the double-stranded DNA by breaking hydrogen bonds
2. RNA primase synthesises a primer at the 3' end of both template strands
3. DNA polymerase moves in a 5' to 3' direction, attaching the stockpiles of free-floating nucleotide bases to the template strand according to the base pairing rule
4. DNA ligase joins the fragments of DNA together

Biology24123

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Re: VCE Biology Question Thread
« Reply #6849 on: October 29, 2015, 12:33:36 pm »
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Thanks!

So where would you add the formation of Okazaki fragments in the process of DNA replication below?

1. DNA helicase unwinds the double-stranded DNA by breaking hydrogen bonds
2. RNA primase synthesises a primer at the 3' end of both template strands
3. DNA polymerase moves in a 5' to 3' direction, attaching the stockpiles of free-floating nucleotide bases to the template strand according to the base pairing rule
4. DNA ligase joins the fragments of DNA together

It's not one of the major steps but after 3. Also, isn't it DNA primase?

BakedDwarf

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Re: VCE Biology Question Thread
« Reply #6850 on: October 29, 2015, 12:43:39 pm »
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It's not one of the major steps but after 3. Also, isn't it DNA primase?

idk. But in exampro, it said RNA primase.

vox nihili

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Re: VCE Biology Question Thread
« Reply #6851 on: October 29, 2015, 01:36:41 pm »
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Thanks!

So where would you add the formation of Okazaki fragments in the process of DNA replication below?

1. DNA helicase unwinds the double-stranded DNA by breaking hydrogen bonds
2. RNA primase synthesises a primer at the 3' end of both template strands
3. DNA polymerase moves in a 5' to 3' direction, attaching the stockpiles of free-floating nucleotide bases to the template strand according to the base pairing rule
4. DNA ligase joins the fragments of DNA together

All of what's been said on Okazaki fragments is fine, but I just want to remind everyone that ligase is only used to put together Okazaki fragments. It really has no other purpose
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Biology24123

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Re: VCE Biology Question Thread
« Reply #6852 on: October 29, 2015, 01:39:13 pm »
0
Does anyone know why having parallel toes is efficient for bipedalism. And is the main development of pelvis to change the centre of gravity for bipedalism

tashhhaaa

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Re: VCE Biology Question Thread
« Reply #6853 on: October 29, 2015, 01:55:00 pm »
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is it essential to know the details of all the types of mutations?

Biology24123

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Re: VCE Biology Question Thread
« Reply #6854 on: October 29, 2015, 01:58:17 pm »
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is it essential to know the details of all the types of mutations?

Yes