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March 19, 2024, 02:47:41 pm

Author Topic: VCE Biology Question Thread  (Read 3563241 times)  Share 

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Chocolatepistachio

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Re: VCE Biology Question Thread
« Reply #12735 on: July 05, 2020, 06:23:57 pm »
+4
Thank you 1729 and owlbird83

Chocolatepistachio

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Re: VCE Biology Question Thread
« Reply #12736 on: July 06, 2020, 11:08:57 am »
+1
Hello would someone be able to help me fill this out
thanks

Owlbird83

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Re: VCE Biology Question Thread
« Reply #12737 on: July 06, 2020, 11:45:59 am »
+8
Hello would someone be able to help me fill this out
thanks

Hey, I attached some feedback.

I really hope that this is something you'll learn from and not copy down passively.

Hope it helps (let me know if anything is unclear)
« Last Edit: July 06, 2020, 11:48:23 am by Owlbird83 »
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Chocolatepistachio

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Re: VCE Biology Question Thread
« Reply #12738 on: July 06, 2020, 12:31:26 pm »
0
Thank you that was very helpful
also i'm not sure about my answers for these if someone could give feedback


Owlbird83

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Re: VCE Biology Question Thread
« Reply #12739 on: July 06, 2020, 02:19:56 pm »
+2
Thank you that was very helpful
also i'm not sure about my answers for these if someone could give feedback

1. Add something about rabbits not having natural predators in Australia to control the numbers, like they did in England, because they didn't evolve with the Australian food chains. (If you look at the question as a whole it's asking about what differs in Aus from Eng, so it would be better to make a statement of comparison, rather than just focus on Australia imo). Also, I would add about why they are pests, not only the large numbers but also that they are detrimental to agriculture/compete for the same niche with our native animals.

4. It would be incorrect to say that 'relatives in England would not have developed resistance since the virus was not introduced in England'. You should assume that there are small numbers of rabbits in England with the resistance genes, but there are no environmental selection pressures there that will cause that trait to increase in frequency because it doesn't give them any advantage. I'd write that the Australian population has a much higher frequency of virus resistant rabbits, due to this trait being advantageous to survival here, but not in England
« Last Edit: July 06, 2020, 02:24:42 pm by Owlbird83 »
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humanbeing

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Re: VCE Biology Question Thread
« Reply #12740 on: July 06, 2020, 04:10:25 pm »
+1
Hi!

1. Does the position of the centromere of a chromosome (metacentric, submetacentric, acrocentric etc) affect the cell cycle or anything else? (I feel like the telocentric centromere wouldn't hold as much DNA)
2. (this is more just out of curiousity) : why is it two "daughter" cells rather than two "son" cells? Do "son" cells even exist?

TIA :)

1729

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Re: VCE Biology Question Thread
« Reply #12741 on: July 06, 2020, 04:50:19 pm »
+3
1. Does the position of the centromere of a chromosome (metacentric, submetacentric, acrocentric etc) affect the cell cycle or anything else? (I feel like the telocentric centromere wouldn't hold as much DNA)
Hey there humanbeing! Welcome to the forum!
They typically are placed in the centre, but they can also be on like the mid-region or wherever on the chromosome. There's different names for these locations metacentric, submetacentric, acrocentric, and telocentric. Shouldn't usually affect cell split, but anomalies can be seen in cancer cells.
2. (this is more just out of curiousity) : why is it two "daughter" cells rather than two "son" cells? Do "son" cells even exist?
This just a naming convention, because it makes sense that daughter cells grow up to become mother cells to divide into more daughter cells.

Quote from: https://biology.stackexchange.com/
During the days when philosophers used to debate, they tended to regard reproduction as a feminine trait. So naturally organisms/cells capable of producing offspring are also given a feminine trait. The parent cell is often called the mother cell, and the daughter cells are so named because they eventually become mother cell themselves.

I presume there exists a similar argument for sister chromatids, in that they are identical. When they separate, they are usually termed as undivided chromosomes.
« Last Edit: July 06, 2020, 04:53:12 pm by 1729 »

Chocolatepistachio

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Re: VCE Biology Question Thread
« Reply #12742 on: July 06, 2020, 05:58:15 pm »
+1
I'm not sure if my answers for these questions are correct if someone could give feedback
Thanks!


Owlbird83

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Re: VCE Biology Question Thread
« Reply #12743 on: July 06, 2020, 08:02:17 pm »
+7
I'm not sure if my answers for these questions are correct if someone could give feedback
Thanks!

Looks good.
In Q2, I'd add that the are in the minority, because having the resistance did not give them a survival advantage at that time.
In Q3, you are kind of giving the same answer for each part, so I think in part a, maybe add that the size of the population would dramatically decrease, as the non resistant insects are all killed off.
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Chocolatepistachio

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Re: VCE Biology Question Thread
« Reply #12744 on: July 06, 2020, 08:21:06 pm »
+1
Ok thanks
And for this question:
Explain why some people use the experience with ddt to support the theory of evolution by natural selection.

- DDt is an example of evolution by natural selection. There is a change in the environment- ddt is introduced some insects have a genetic resistance to the virus. The insects with the gene survive and reproduce and over time the population of ddt resistant insects increases. 

Owlbird83

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Re: VCE Biology Question Thread
« Reply #12745 on: July 07, 2020, 09:37:38 am »
+6
Ok thanks
And for this question:
Explain why some people use the experience with ddt to support the theory of evolution by natural selection.

- DDt is an example of evolution by natural selection. There is a change in the environment- ddt is introduced some insects have a genetic resistance to the virus. The insects with the resistance gene are more likely to survive and reproduce and therefore over time the frequency of the resistant insects increases in the insectpopulation.
It was good I reckon, but I modified it a bit. (Mainly the part where the you said the resistant insects survive and reproduce, it would be better to write that they have a survival advantage over the others). (The last part was probably okay how you wrote it, but I would write that the frequency increases in the population because it suggests that the non resistant insects are decreasing also.)
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Bri MT

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Re: VCE Biology Question Thread
« Reply #12746 on: July 07, 2020, 11:38:09 am »
+5
Ok thanks
And for this question:
Explain why some people use the experience with ddt to support the theory of evolution by natural selection.

- DDt is an example of evolution by natural selection. There is a change in the environment- ddt is introduced some insects have a genetic resistance to the virus. The insects with the gene survive and reproduce and over time the population of ddt resistant insects increases. 

I'd modify your wording slightly to indicate that DDT itself isn't an example of evolution (the population genetically changing to become more DDT resistant is evolution) & refer to different genotypes or alleles rather than different genes. As owlbird has indicated it's also a good idea to modify some of your other language to more accurately reflect the situation.

Chocolatepistachio

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Re: VCE Biology Question Thread
« Reply #12747 on: July 07, 2020, 03:56:15 pm »
+1
Hello
For this question:
Penicillin is an antibiotic that either slows the growth or kills dangerous bacteria such as staphylococcus aureus. In the pre antibiotic era more than 80%of patients suffering from staphylococcus aureus bacteraemia (blood poisoning) died. In the early 1940s few of these bacteria were resistant to penicillin and many lives were saved. By 1950 50% of the bacteria had developed resistance and this increased to 60% by the 1960s
Explain in terms of natural selection how this happened.

- Before penicillin was introduced not many bacteria had the resistant gene. After Penicillin was introduced the number of bacteria with the resistance increased and reproduce and pass on the trait

Sine

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Re: VCE Biology Question Thread
« Reply #12748 on: July 07, 2020, 04:33:03 pm »
+5
Hello
For this question:
Penicillin is an antibiotic that either slows the growth or kills dangerous bacteria such as staphylococcus aureus. In the pre antibiotic era more than 80%of patients suffering from staphylococcus aureus bacteraemia (blood poisoning) died. In the early 1940s few of these bacteria were resistant to penicillin and many lives were saved. By 1950 50% of the bacteria had developed resistance and this increased to 60% by the 1960s
Explain in terms of natural selection how this happened.

- Before penicillin was introduced not many bacteria had the resistant gene. After Penicillin was introduced the number of bacteria with the resistance increased and reproduce and pass on the trait
Good start but could elaborate a bit further. Maybe talk about why the introduction fo penicillin increased the number of bacteria with the resistance?

1729

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Re: VCE Biology Question Thread
« Reply #12749 on: July 07, 2020, 04:36:01 pm »
+4
Hello
For this question:
Penicillin is an antibiotic that either slows the growth or kills dangerous bacteria such as staphylococcus aureus. In the pre antibiotic era more than 80%of patients suffering from staphylococcus aureus bacteraemia (blood poisoning) died. In the early 1940s few of these bacteria were resistant to penicillin and many lives were saved. By 1950 50% of the bacteria had developed resistance and this increased to 60% by the 1960s
Explain in terms of natural selection how this happened.

- Before penicillin was introduced not many bacteria had the resistant gene. After Penicillin was introduced the number of bacteria with the resistance increased and reproduce and pass on the trait
I don't know how many marks this question is, but I feel like you need to expand a little more. After your first sentence, mention that penicillin kills other bacteria that did not contain or possess the resistant gene, thus leaving the resistant bacteria with no competition. This allowed them to flourish and reproduce passing on the resistant trait with less competition (due to less bacteria being present). This increases resisistant to penicillin within a bacterial population as they reproduce and pass on the trait. ALSO antibiotic resistant bacteria can transfer this resistance by transferring plasmids through bacterial conjugation and this can further increase resistance in a population and as this bacteria thrives and other ones die, the resistant bacteria reproduce and pass on trait.