HSC Biology Question Thread

[PhoenixxFire]

Hi...

What is the difference between independent assortment and random segregation? I always get confused between these two...

Random segregation means that homologous chromosomes are randomly placed into the daughter cells. Independent assortment means that which of a homologous chromosome is placed into a daughter cell has no effect on which copy of a different chromosome is placed into the same daughter cell.

That's why when genes are independent it means that they're on different chromosomes. So if gene A and gene B are on different chromosomes (lets say gene A is on 13 and gene B is on 20) then getting allele A (located on the first homologous copy of chromosome 13) of gene A does not affect whether you will get allele A (chromosome 20, copy 1) or allele B (chromosome 20, copy 2) of gene B.

When genes are linked they're on the same chromosome - so they don't assort independently and are generally inherited together (barring things like crossing over separating them).

[martinarena_]

Hi there!
Just had a quick question regarding the Biotechnology Syllabus - for the following dot points do we only choose one of the suggested or was it providing an example for EACH of the ones they've listed? (bit of a stupid question, but the wording of the dot point just hit me hard haha)
•   describe one example from the following applications of aquaculture:
ー   production of a pharmaceutical from algae
ー   farming of a marine animal
•   describe one example from the following applications of animal or plant biotechnology:
ー   production of monoclonal antibodies
ー   recombinant vaccines to combat virulent animal diseases
•   describe one example from the following applications of biotechnology in medicine:
ー   tissue engineering using skin transplantation as an example
ー   gene delivery by nasal sprays
ー   production of a synthetic hormone, such as insulin

Thank you in advance !

[Ace2018]

HEY GUYS! TO ANYONE DOING MALARIA AS AN INFECTIOUS DISEASE, WHAT IS THE HOST RESPONSE? I'VE DUG THROUGH THE INTERNET HIGH AND LOW BUT KEEP ENDING UP IN COMPLEX REPORTS AND ARTICLES THAT ARE REALLY IN DEPTH AND WAY BEYOND THE BIO SYLLABUS. ANY HELP WOULD BE APPRECIATED!

[martinarena_]

HEY GUYS! TO ANYONE DOING MALARIA AS AN INFECTIOUS DISEASE, WHAT IS THE HOST RESPONSE? I'VE DUG THROUGH THE INTERNET HIGH AND LOW BUT KEEP ENDING UP IN COMPLEX REPORTS AND ARTICLES THAT ARE REALLY IN DEPTH AND WAY BEYOND THE BIO SYLLABUS. ANY HELP WOULD BE APPRECIATED!

Hi there!
Basically, when the plasmodium is inside the human liver (where it produces asexually) it is isolated from the host's immune response. However, when the merozoites (daughter parasites) are released from the liver and enter the red blood cells, this is when the host begins to produce antibodies against it - but get this, the surface antigens of the plasmodium actually changes periodically! This allows it to avoid the host's immune response - therefore the changing surface antigens are not recognised by the antibodies already produced by the host.

Hope this is helpful 

[charlottemchenry]

Hey,

In regards to 'evaluate' and 'assess' questions for Biology are we allowed to be half half...

Like for English and Legal, often I'll say "somewhat effectiveness" or "mostly effective" however when I've read aloud bio answers in class despite me giving both positive and negative things whenever I say "somewhat" my teacher says we have to choose one or the other.

I just wanted to check if this is actually the case or in the HSC can we be on the fence?

Thank you

[kauac]

Hey,

In regards to 'evaluate' and 'assess' questions for Biology are we allowed to be half half...

Like for English and Legal, often I'll say "somewhat effectiveness" or "mostly effective" however when I've read aloud bio answers in class despite me giving both positive and negative things whenever I say "somewhat" my teacher says we have to choose one or the other.

I just wanted to check if this is actually the case or in the HSC can we be on the fence?

Thank you

Hi...

Let's take a look at the NESA definitions for each:

Evaluate: Make a judgement based on criteria; determine the value of.
Assess: Make a judgement of value, quality, outcomes, results or size.

So it is very clear that you need to make a judgement, and you techniquely have, by saying it is 'somewhat effective'. However, this choice of words can sometimes come across as too much like a discuss question, and you cannot really show a clear judgement and still sit at 50/50. Thus, it is always best to pick one side. You can still show in minor ways how they are / aren't effective (this shows you have thought about your response), but really emphasise which side you are taking - especially at the start and end of your answer.

Hope this helps. 

[charlottemchenry]

Hi...

Let's take a look at the NESA definitions for each:

Evaluate: Make a judgement based on criteria; determine the value of.
Assess: Make a judgement of value, quality, outcomes, results or size.

So it is very clear that you need to make a judgement, and you techniquely have, by saying it is 'somewhat effective'. However, this choice of words can sometimes come across as too much like a discuss question, and you cannot really show a clear judgement and still sit at 50/50. Thus, it is always best to pick one side. You can still show in minor ways how they are / aren't effective (this shows you have thought about your response), but really emphasise which side you are taking - especially at the start and end of your answer.

Hope this helps. 

Thanks so much that makes sense

[edumax]

HOW THE HECK DO YOU STUDY EFFECTIVELY FOR BIO???
It's too overwhelming to know where to start 

[Owlbird83]

HOW THE HECK DO YOU STUDY EFFECTIVELY FOR BIO???
It's too overwhelming to know where to start 

I did A4 sheets for each topic and did a mind map of key points, using my textbook and notes and the study design. I think it sort of helps to organise the big jumble of information.
Also, do practice exams and then you can identify areas where you need to focus more on.
Hope this helps

[Razeen25]

Hi there!
Just had a quick question regarding the Biotechnology Syllabus - for the following dot points do we only choose one of the suggested or was it providing an example for EACH of the ones they've listed? (bit of a stupid question, but the wording of the dot point just hit me hard haha)
•   describe one example from the following applications of aquaculture:
ー   production of a pharmaceutical from algae
ー   farming of a marine animal
•   describe one example from the following applications of animal or plant biotechnology:
ー   production of monoclonal antibodies
ー   recombinant vaccines to combat virulent animal diseases
•   describe one example from the following applications of biotechnology in medicine:
ー   tissue engineering using skin transplantation as an example
ー   gene delivery by nasal sprays
ー   production of a synthetic hormone, such as insulin

Thank you in advance !

I don't do biotech, but maybe look through all the past papers for biology up till 2001, and see if they've ever specified one of those and generally ask for an example

[amelia20181]

When blood pressure drops, the body responds by:
A) releasing ADH to increase reabsorption of water
B) releasing ADH to increase uptake of salts
C) releasing aldosterone to increase reabsorption of water
D) releasing aldosterone to increase uptake of salts


Why is the answer for this question A and not d

[amelia20181]

This isn’t  from a past paper

[terassy]

When blood pressure drops, the body responds by:
A) releasing ADH to increase reabsorption of water
B) releasing ADH to increase uptake of salts
C) releasing aldosterone to increase reabsorption of water
D) releasing aldosterone to increase uptake of salts


Why is the answer for this question A and not d

Can't be B or C. So either A or D, since it's talking about blood pressure the answer should be D.

[Mate2425]

Hey guys was wondering if someone could please give me a thorough explanation to HSC 2017 MCQ9. and MC.Q20.
https://educationstandards.nsw.edu.au/wps/wcm/connect/fc23024b-f91e-468c-90b5-8d522b8d2dbf/2017-hsc-biology.pdf?MOD=AJPERES&CACHEID=ROOTWORKSPACE-fc23024b-f91e-468c-90b5-8d522b8d2dbf-m0Qr1Ki
Many thanks 

[Razeen25]

Hii, I was wondering if someone could clarify this Genetics for point as I find it really confusing: ‘Explain how the use of recombinant DNA technology can identify the position of a gene on a chromosome.’

My understanding is this:
1. A restriction enzyme is used to cut a section of DNA
2. The fragments are placed on gel where electrical impulses cause fragments to separate by size (gel electrophoresis).
3. The fragments are then stained by fluorescent dye which glows, and cut again.
4. A radioactive probe (single stranded sequence of DNA that is complementary to the gene) is are tagged with radioactive marker, and attached to complementary gene and inserted into human chromosome.
5. When a light is shone, the probe glows showing the location of the gene.

That’s what I recall from reading notes, however I don’t understand how the process (if that’s even correct) is recombinant DNA technology or why original DNA is cut up TWICE and probe isn’t just added in initially ugh smh.

Any help would be greatly appreciated (.