HSC Biology Question Thread

[charlottemchenry]

What if you write below the lines of 6 lines for example and there so space can’t you just write on the black space provided ??

OMG I was wondering the exact same thing!

[jasn9776]

OMG I was wondering the exact same thing!

yes you are allowed to use the blank space. I know this isn't for all subjects but yes, I have confirmation from the HSC4ME UTS live chat biology marker that you can.

[kauac]

Producing transgenic species:
increases or decreases genetic diversity?
(I asked my teacher this, she didn't know the answer.  )

[vox nihili]

Producing transgenic species:
increases or decreases genetic diversity?
(I asked my teacher this, she didn't know the answer.  )

Decreases. Let me know your thoughts on why you think this is

[kauac]

Decreases. Let me know your thoughts on why you think this is

Well, I originally thought that it would create new combination of genes (hence the increase)...

But when producing transgenic species, they make heaps of copies of the same gene to insert - which makes one allele more common than the others. I'm not sure if this is the correct reasoning for why genetic diversity decreases, or just something else I have observed?

[charlottemchenry]

Well, I originally thought that it would create new combination of genes (hence the increase)...

But when producing transgenic species, they make heaps of copies of the same gene to insert - which makes one allele more common than the others. I'm not sure if this is the correct reasoning for why genetic diversity decreases, or just something else I have observed?

Hey, So I too was so confused about this. I think this is right based on questions I've seen and it sorta makes sense with like the biological principles we learn.

From what I've gathered initially it increases genetic diversity as new genes are being introduced. However over time these favourable characteristics will survive and hence eventually decrease genetic diversity.

I saw like a 5 marker on this saying short and long term effects I think and also a mc with a table and it was like short term long term and had transgenic and something else like say cloning and you had to pick the correct row. Sorry I don't remember where the question was from.

Hope this helps.

[vox nihili]

Well, I originally thought that it would create new combination of genes (hence the increase)...

But when producing transgenic species, they make heaps of copies of the same gene to insert - which makes one allele more common than the others. I'm not sure if this is the correct reasoning for why genetic diversity decreases, or just something else I have observed?

Hey, So I too was so confused about this. I think this is right based on questions I've seen and it sorta makes sense with like the biological principles we learn.

From what I've gathered initially it increases genetic diversity as new genes are being introduced. However over time these favourable characteristics will survive and hence eventually decrease genetic diversity.

I saw like a 5 marker on this saying short and long term effects I think and also a mc with a table and it was like short term long term and had transgenic and something else like say cloning and you had to pick the correct row. Sorry I don't remember where the question was from.

Hope this helps.

Good on you both for thinking through this question. By and large I think you've got the right idea.

My reason for saying decrease was the practicalities of transgenic organisms. We tend to use transgenic organisms to replace organic organisms. For instance, we foritifed rice with vitamin A making genes and then planted this rice instead of native rices. The effect of this is to decrease the diversity in rice crops, even though we've technically added a gene to the gene pool. This is one of the most pressing concerns with the use of GMOs, which despite what some groups might say, are safe but do decrease diversity and therefore potentially increase the risk of catastrophic famines if a change in the environment prevails to kill that crop (less diversity means less capacity to deal with the change).

[charlottemchenry]

Good on you both for thinking through this question. By and large I think you've got the right idea.

My reason for saying decrease was the practicalities of transgenic organisms. We tend to use transgenic organisms to replace organic organisms. For instance, we foritifed rice with vitamin A making genes and then planted this rice instead of native rices. The effect of this is to decrease the diversity in rice crops, even though we've technically added a gene to the gene pool. This is one of the most pressing concerns with the use of GMOs, which despite what some groups might say, are safe but do decrease diversity and therefore potentially increase the risk of catastrophic famines if a change in the environment prevails to kill that crop (less diversity means less capacity to deal with the change).

Yeah I 100% agree, just based on HSC questions I've seen I've noticed a few do say short term increase which is tricky as you pointed out the aim is to decrease the diversity. I think it's cause they want you to use your knowledge of natural selection and evolution.

Thank you!

[vox nihili]

Yeah I 100% agree, just based on HSC questions I've seen I've noticed a few do say short term increase which is tricky as you pointed out the aim is to decrease the diversity. I think it's cause they want you to use your knowledge of natural selection and evolution.

Thank you!

Whether or not there is an increase depends on how the transgenic organism is used. Remember, if you take 1000 rice plants from a single transgenic organism, the variation in that population is 0. So if that crop then replaces another, it has to decrease diversity (because the new crop has none). If anything diversity increases over time as the transgenic organism evolves.

[3.14159265359]

hey can someone please tell me how to approach the long response question and what I should include. and for the multiple choice I'm really confused because my punnet square showed that only 1 child(25%) should get the disease but there is already one child. so how can the answer be b?

thank you!!

[charlottemchenry]

. and for the multiple choice I'm really confused because my punnet square showed that only 1 child(25%) should get the disease but there is already one child. so how can the answer be b?

thank you!!

So by doing the punnet square with Rr and Rr you got RR, Rr, Rr and rr. Hence 25% chance that a child will be affected. Having one child doesn't decrease the chance that the next will also have it. So there's still a 25% chance.

[jasn9776]

hey can someone please tell me how to approach the long response question and what I should include.?

thank you!!

looking at it i'm as stumped as you. but looking at the sample answer:
https://educationstandards.nsw.edu.au/wps/wcm/connect/e3d9318d-2d4c-4084-8164-4b9198813e07/biology-hsc-sa-2011.pdf?MOD=AJPERES&CACHEID=ROOTWORKSPACE-e3d9318d-2d4c-4084-8164-4b9198813e07-lyVfTRI
it seems that you need to look at the advances that led to the development of the fungus i.e. bacterium understanding as a pathogen. DNA mutation using radiation and understanding of antibiotics. Then it actually goes on to describe the benefits of the technology like fewer deatsh due to infection, etc.

[olliclark4]

What do we need to know re: Meiosis? My understanding is quite weak so id love to know exactly what parts i need to understand.

[kauac]

hey can someone please tell me how to approach the long response question and what I should include. and for the multiple choice I'm really confused because my punnet square showed that only 1 child(25%) should get the disease but there is already one child. so how can the answer be b?

thank you!!

Just to add on from what jasn9776 has already said,
You could also talk about:
- Enzyme specificity to their substrate (lock and key model)
- One gene-one polypeptide and Beadle/Tatum's neurospora findings.

It is actually a very broad question, and gives you scope to choose the areas of biological understanding you feel most confident with, to expand on.

[3.14159265359]

hELLOO
I NEED URGENT HELP

DIFFERENCE BETWEEN CELL DIFFERENTIATION AND CELL SPECIALISATION

I READ THROUGH SO MANY NOTES AND EACH IS DIFFERENT TO THE PREVIOUS ONE

THANK YOUU