HSC Biology Question Thread

[phebsh]

Hi all, what is an experiment that models natural selection? One which is not the basic peppered moth example... Thanks! 

[Paul.I]

Hi all, what is an experiment that models natural selection? One which is not the basic peppered moth example... Thanks! 

An experiment that models natural selection:
Have two peaces of paper (different, but similar enough to make it realistic e.g. yellow and green)
Consider the green to be your grass/environment
From here cut up a sheet of the yellow paper and a sheet of green paper into equal sizes and scrunch then up and place into a beaker. (these are your animals/insects)
On your green peace of paper spread the crumpled 'insects'
Using a timer, time 20s and pick up as many peaces of paper as possible and place into the beaker using tweezers
Record your result (how many green picked and how many yellow)
Place back the peaces of paper from the beaker onto the green paper and repeat a further 9 times
Take an average of your 10 results.

You will notice that the yellow is picked up a lot more frequently than the green because it doesn't have the desirable trait of being able to camouflage into the background like the green can. Same thing happens in real life as you know with the peppered moth.
You can talk about limitations how the papers don't move like real animals do, not equal populations of each etc..

[Snew]

Question: compare the role of haemoglobin in transporting oxygen and carbon dioxide. Having trouble pulling together a succinct answer. Thanks 

[sweetcheeks]

Question: compare the role of haemoglobin in transporting oxygen and carbon dioxide. Having trouble pulling together a succinct answer. Thanks 

For oxygen to be able to circulate around the body, it needs to bind to the haemoglobin, as oxygen gas by itself has a low solubility in plasma. Carbon dioxide on the other hand, is much more soluble in the plasma, where it forms carbonic acid (and some free CO2). Only a small percentage of the CO2 circulating around the body is bound to haemoglobin.

From this information, are you able to put together a sufficient answer? Perhaps compare the importance of haemoglobin in the transport of both substances?

[Wren]

Can someone help me answer this question?
Compare the chemical composition of blood arriving at the glomerulus with the composition of glomerular filtrate?

[phebsh]

Hey! I'm struggling with this issue in regards to Biology; I can understand the content that is taught to me, and while studying, but find it difficult to answer exam-style questions. How do I overcome this? Thanks

[sweetcheeks]

Hey! I'm struggling with this issue in regards to Biology; I can understand the content that is taught to me, and while studying, but find it difficult to answer exam-style questions. How do I overcome this? Thanks

Practice. I had the same difficulty, I knew the content but I was unable to clearly and concisely state a point. You have to keep doing questions to build up the skill to be able to do so. Look at some of the key words that are used in answers, as these can be used in your answer allowing it to be better understood and more concise.

[jabuibui]

Is DNA hybridisation a form of DNA fingerprinting?

[Kirri Rule]

Hi thanks in advanced but i am currently really struggling with studying and remembering all the little details in the course that always seem to show up on practice papers. Does anyone have any pointers??

[jamonwindeyer]

Hi thanks in advanced but i am currently really struggling with studying and remembering all the little details in the course that always seem to show up on practice papers. Does anyone have any pointers??

Hey Kirri! I didn't do Bio, but I thought I'd recommend this guide! Hopefully it has a few ideas you can use

[Mathew587]

Hey Kirri,
The only thing I can recommend is to make better notes that cover these points and repeatedly revise these points. Also do more questions on whatever you dont understand. Its better to go through the difficulty now and get it wrong than go through the difficulty and get it wrong in the actual HSC exam

[bananna]

hihi!

I'm making notes for 'blueprint' and was wondering if you could check my table I'm wanting to study off

Is there anything I should add or remove/ is anything inaccurate?

Also, how would I go about answering a question regarding this dotpoint?

thank you!!!!

[Kirri Rule]

Hey Kirri! I didn't do Bio, but I thought I'd recommend this guide! Hopefully it has a few ideas you can use

Wow thank you so much i didn't see that before that has some really good points thanks!

[Kirri Rule]

Hey Kirri,
The only thing I can recommend is to make better notes that cover these points and repeatedly revise these points. Also do more questions on whatever you dont understand. Its better to go through the difficulty now and get it wrong than go through the difficulty and get it wrong in the actual HSC exam

Thank you, do you normally go through the questions then mark them with your teacher or by yourself?

[stephanieazzopardi]

hihi!

I'm making notes for 'blueprint' and was wondering if you could check my table I'm wanting to study off

Is there anything I should add or remove/ is anything inaccurate?

Also, how would I go about answering a question regarding this dotpoint?

thank you!!!!

Hi there!
Your table is great and very detailed and you have included all the right scientists
In terms of how the development of their respective theories were influenced by society and politics, you could add these points to Darwin's theory:

• 1920's: Protestants campaigned against anti-biblical ideas of evolution
• Several US States: passed legislation which banned the teaching of evolution in public schools

[li]1925: teacher from Tennessee arrested and put on trial for teaching the theory of evolution
[/li][/list]

In terms of answering a question on this dot point, I would do a paragraph for each of the three theories of evolution you have listed or a paragraph for each person (1. Lamarck 2. Darwin 3. Wallace). You would start of each by explaining the theories, their evidence and then the social and political influences.

Hope this helped!