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March 29, 2024, 02:19:40 am

Author Topic: VCE Biology Question Thread  (Read 3570633 times)  Share 

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Phoenix11

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Re: VCE Biology Question Thread
« Reply #10620 on: September 02, 2018, 11:11:44 am »
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Thank you for the help PhoenixxFire!
 :) :)
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jacquieg

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Re: VCE Biology Question Thread
« Reply #10621 on: September 03, 2018, 11:56:29 am »
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Can someone explain the difference between genetic flow and genetic drift please? I always get them confused
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PhoenixxFire

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Re: VCE Biology Question Thread
« Reply #10622 on: September 03, 2018, 12:01:20 pm »
+3
Can someone explain the difference between genetic flow and genetic drift please? I always get them confused
Genetic flow: changes in the genetic makeup of a population due to individuals moving between populations.

Genetic drift: changes in the genetic makeup of a population due to random individuals dying or not reproducing.

To help remember it:
If something is flowing it’s moving from one place to another (the individuals are moving between populations).

If something is drifting it’s just floating along whichever way it happens to go (the genetic makeup changes due to random deaths).
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PopcornTime

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Re: VCE Biology Question Thread
« Reply #10623 on: September 04, 2018, 09:36:27 am »
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Are the following PCR steps ok?

Denaturation: temperature is increased to around 92ºC, which separates double-stranded DNA into two template strands

Annealing: temperature is reduced to around 55ºC, which allows primers to bind to template strands

Extension: temperature is increased to around 72ºC, which allows Taq Polymerase to assemble a complementary DNA strand

Do I need to say temperature of the PCR mix is increased to around...etc.

Sine

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Re: VCE Biology Question Thread
« Reply #10624 on: September 04, 2018, 10:04:17 am »
+2
Are the following PCR steps ok?

Denaturation: temperature is increased to around 92ºC, which separates double-stranded DNA into two template strands

Annealing: temperature is reduced to around 55ºC, which allows primers to bind to template strands

Extension: temperature is increased to around 72ºC, which allows Taq Polymerase to assemble a complementary DNA strand

Do I need to say temperature of the PCR mix is increased to around...etc.
yeah the temperatures are important. I think the first temp is closer to 95C. Also you should refer to Hydrogen bonds being broken at this temperature. This question has been asked before on VCAA exams so check the assesors report to be 100% sure you have covered everything for full marks.

peachxmh

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Re: VCE Biology Question Thread
« Reply #10625 on: September 05, 2018, 08:09:28 pm »
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Can restriction enzymes cut RNA?

Edit: just wanted to add one more q - would it be safer to say that recombinant DNA is DNA formed from combining fragments of DNA molecules from different SPECIES or ORGANISMS?

 ;D thanks !!
« Last Edit: September 05, 2018, 08:30:37 pm by peachxmh »
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Erutepa

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Re: VCE Biology Question Thread
« Reply #10626 on: September 06, 2018, 11:13:53 am »
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Can restriction enzymes cut RNA?

Edit: just wanted to add one more q - would it be safer to say that recombinant DNA is DNA formed from combining fragments of DNA molecules from different SPECIES or ORGANISMS?

 ;D thanks !!
I think the most general thing to say is that recombinant DNA is DNA formed from combining fragments from multiple different sources. I think In most cases this will be applied to questions where a bacteria is being transformed with a recombinant plasmid made using a human gene.

Yes, some restriction enzymes have been observed to cleave RNA strands, but I don't think you will need to know this.
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PopcornTime

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Re: VCE Biology Question Thread
« Reply #10627 on: September 06, 2018, 09:01:55 pm »
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I'm still having a bit of trouble understanding the relationship between primates, hominoids and hominins.

Can someone confirm the following:

primates: group of mammals, including humans, great apes and monkeys

Hominoids: group including modern and extinct great apes

Hominins: group including modern humans, extinct human species and all immediate ancestors.

Also, what does it mean by "great apes"?

Monkeymafia

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Re: VCE Biology Question Thread
« Reply #10628 on: September 08, 2018, 01:54:53 pm »
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So over time there are genetic differences between two species.

Are these genetic differences mainly due to mutations or can there be other reasons?

Sine

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Re: VCE Biology Question Thread
« Reply #10629 on: September 08, 2018, 02:12:25 pm »
+1
So over time there are genetic differences between two species.

Are these genetic differences mainly due to mutations or can there be other reasons?
mutations but could also be in addition reproductive isolation (no gene flow between two populations of the same species)

PhoenixxFire

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Re: VCE Biology Question Thread
« Reply #10630 on: September 08, 2018, 02:25:57 pm »
+3
So over time there are genetic differences between two species.

Are these genetic differences mainly due to mutations or can there be other reasons?
All new alleles are due to mutations however things like genetic drift and selection pressures could change the frequency of alleles or wipe out specific alleles entirely, if this happens differently for each species then they will end up with genetic differences.
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Agimo

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Re: VCE Biology Question Thread
« Reply #10631 on: September 09, 2018, 03:59:31 pm »
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What is the difference between structural and regulatory genes? Different sources contradict eachother so im not really sure what VCAA wants us to know

PhoenixxFire

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Re: VCE Biology Question Thread
« Reply #10632 on: September 09, 2018, 04:05:23 pm »
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What is the difference between structural and regulatory genes? Different sources contradict eachother so im not really sure what VCAA wants us to know
Regulatory genes produce a gene product that is involved in the expression of other genes.
Structural genes produce a gene product that is involved in normal cellular metabolism.
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Azim.m

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Re: VCE Biology Question Thread
« Reply #10633 on: September 09, 2018, 09:09:52 pm »
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By which process do calcium ions enter the presynaptic terminal? Active transport or facilitated diffusion?

PopcornTime

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Re: VCE Biology Question Thread
« Reply #10634 on: September 09, 2018, 09:32:02 pm »
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Active Transport. Ions generally move by active transport in general.