HSC Biology Question Thread

[bananna]

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!

awesome!!
thank you so much

[Shania.k]

Hey
I was wondering if there was a simple way to remember the Nephron and all its components and what they do, I've drawn it so many times but can never get the labels right!!

[kiiaaa]

Hello,

could you please explain me the difference between ADH and aldostrone and any tips and tricks to remember the two what they do and the differences. im a pro and confusing the two
Thank you!

[Sukakadonkadonk]

Hello,

could you please explain me the difference between ADH and aldostrone and any tips and tricks to remember the two what they do and the differences. im a pro and confusing the two
Thank you!

Ok so basically, these are both hormones and both act on the kidneys. And also, I think that they both restabilise the blood pressure.

ADH - Antidiuretic hormone
- released from the hypothalamus in the brain
- response to low water levels in the blood
- increases permeability of tubule walls in nephron
- low water -> release of ADH -> more water reabsorbed into the blood

Aldosterone
- released from adrenal glands
- response to drop in blood pressure and low water levels
- also controls reabsorption of solutes (sodium)
- low water/minerals in blood -> release of Aldosterone -> more solutes and water reabsorbed into blood

I guess a way to remember which is which is to recall that 'Aldosterone' has more words, hence it causes the absorption or more things into the blood.
Please correct me, anyone, if I'm wrong.

Hope this helped!

[DalvinT]

Hello,

could you please explain me the difference between ADH and aldostrone and any tips and tricks to remember the two what they do and the differences. im a pro and confusing the two
Thank you!

The way I remember it is that:

ADH - fills in THREE spaces with letters
H20 - also fills up with three spaces.
So therefore, I know that ADH has got to do with the water reabsorption...

Leaving:
Aldosterone that involves salt and water reabsoprtion...
 

[bananna]

Hi,

with pedigrees, what is a quick way to determine if the affected trait is dominant or recessive?

thank you!

[Quantum44]

Hi,

with pedigrees, what is a quick way to determine if the affected trait is dominant or recessive?

thank you!

If the trait is recessive they will always show it skipping a generation whereas if the trait is dominant they will always show it being inherited by every generation. Thus you can pretty much tell in a few seconds whether it is dominant or recessive.

For example with recessive two unaffected parents can have affected children but for dominant an affected child must have at least one affected parent.

[anotherworld2b]

thyroxine is secreted by the thyroid gland and controls metabolism (breakdown/build up of molecules)
does that mean the heat that is released is due to both the build up and breaking of molecules?
I was wondering when would thyroxine secretion be triggered? when there is a low body temperature? (to maintain homeostasis maybe?)
I am a bit confused about thyroxin being secreted in response to thyroid stimulating hormone. Is it because TSH stimulates the production and release of hormones from the thyroid gland and thyroxine is one of these hormones? Is thyoxine the only thyroid hormone? does it include parathyroid hormones?
I am quite confused about thyroxine and thyroid stimulating hormone. Help is greatly appreciated

[vox nihili]

thyroxine is secreted by the thyroid gland and controls metabolism (breakdown/build up of molecules)
does that mean the heat that is released is due to both the build up and breaking of molecules?
I was wondering when would thyroxine secretion be triggered? when there is a low body temperature? (to maintain homeostasis maybe?)
I am a bit confused about thyroxin being secreted in response to thyroid stimulating hormone. Is it because TSH stimulates the production and release of hormones from the thyroid gland and thyroxine is one of these hormones? Is thyoxine the only thyroid hormone? does it include parathyroid hormones?
I am quite confused about thyroxine and thyroid stimulating hormone. Help is greatly appreciated

Thyroid hormone does influence metabolism, but it typically favours catabolism (i.e. breakdown of molecules). So the net effect of thyroid hormone is to increase breakdown of molecules, and thus energy production. Build up of molecules almost never produces energy.

Secretion of thyroid hormone is constitutive (meaning always secreted). This is because it is required to maintain your basal metabolic rate. If memory serves, thyroxine production does increase if you're really cold, but this isn't really your traditional homeostatic mechanism. It's more or less an option in crisis.

You're right about the role of TSH. It tells the thyroid to produce and secrete thyroid hormone.
THere are probably plenty of thyroid hormones, but the two we often talk about are thyroxine and triiodothyronine. The one that is actually active is triiodothyronine, hence why I've avoided using the term thyroxine and replacing it with thyroid hormone. The details of these hormones is pretty tricky, but the short and sweet is that thyroxine is a precursor of triiodothyronine.
Parathyroid hormones are distinct to thyroid hormones. The parathyroid glands are completely different structures.

[annablackledge]

How should you answer a question that asks you to analyse a graph? What kind of things do they want you to say?

[sophiegmaher]

Hey! Has anyone got a good structure for 8 marker exam questions, with everything necessary to include to get full marks? Thanks

[sophiegmaher]

When should we use a ruler when drawing graphs? I got marked down for using one, and I'm not sure when you should or shouldn't! Should you only use one when doing a line of best fit and not in a typical plotted-diagram..?

[kiiaaa]

Hello everybody
i was wondering if anyone knew any good sites or places to get past papers for half yearlies. my school doenst release any and i dont know where else to find them
thank you so much!

[annablackledge]

Hello everybody
i was wondering if anyone knew any good sites or places to get past papers for half yearlies. my school doenst release any and i dont know where else to find them
thank you so much!

I personally recommend purchasing the paper copy books of past papers from Excel. But they are big and heavy I use http://www.pasthsc.com.au/HSC.html
and
https://thsconline.github.io/s/yr12/
you can find some on ATAR Notes or Bored of studies

[ajajaj]

Hey guys,
Is a line of best fit curved or straight?? In what cases would you do that in comparison to joining the dots on a graph?