HSC Biology Question Thread

[sidzeman]

Both aldosterone and ADH act on the distal and collecting tubule. Also adding to this there's  also secretion- urea diffuses in at the proximal tubule, whereas hydrogen ions moves into the distal tubule via active transport

Really i thought urea was present in blood and entered the bowmans capsule through the glomerulus? Secretion was only for drugs and poisons in my notes

[angelahchan]

Really i thought urea was present in blood and entered the bowmans capsule through the glomerulus? Secretion was only for drugs and poisons in my notes

Yeah, secretion involves drugs and poisons but there's  more than that. Urea is filtered in bowman's capsule, but not 100% so some secretion is involved . Here's a brief diagram in my notes, it doesn't cover everything tho

[stephjones]

hey guys, how much information to people have for the dot point on the social and political impacts/influences of developing theories of inheritance? the only thing i really have is the whole "they threatened creationist views" but ??

[angelahchan]

hey guys, how much information to people have for the dot point on the social and political impacts/influences of developing theories of inheritance? the only thing i really have is the whole "they threatened creationist views" but ??

Here are my notes, I hope you don't mind that I lazily copied and pasted them. but you definitely don't need to know that much detail, I think the dot point hasn't even been assessed before (not sure tho)
Social and political influences on the development of the theory of evolution
   - Many ideas were put forward during the 1700-1800s, a time of political and social unrest, with the French revolution and industrial revolution
   - People became more interested in science and explaining the structure of matter and how it behaved
   - Erasmus Darwin came up with his vague idea of evolution during the late 1700s
   - Lamarck was doing research at the height of the French Revolution and outlined some main components of his theory
   - His ideas challenged the belief that species were created independently of each other and didn't change
   - This challenged religious and social beliefs, opening the doors for new ideas
   - The social and religious beliefs of times in the past also delayed Darwin publishing is ideas on evolution for 12 years
   - In the 1860s the theory was widely accepted
   - In the early 1900s in the US shifted from traditional beliefs to more modern beliefs.

[angelahchan]

Hi, does anyone know the range in the electromagnetic spectrum that humans, snakes, and bees can see?
my notes says  the range for humans is 380-750nm, but wikipedia says it's 390-700nm

[archie33]

Hi, does anyone know the range in the electromagnetic spectrum that humans, snakes, and bees can see?
my notes says  the range for humans is 380-750nm, but wikipedia says it's 390-700nm

Hey,
Humans: 380-750 nm
Bees: 300-700 nm
Snakes: 480-850 nm
This is what I have, I've checked around and these seem like the common answer. Wikipedia is a bit hard to trust.

[hannahhhh]

Hi I know this is rather late, but I’m really struggling to wrap my mind around interaction between T and B lymphocytes, cell mediated immunity and antibody mediated immunity - I don’t understand it extensively and I don’t really know how much I need to know of it anyway! I would forever appreciate any help at all!!!

[archie33]

Hi,
Do we need to know anything in-depth about MacFarlane Burnet's work? Thanks

[sidzeman]

Yeah, secretion involves drugs and poisons but there's  more than that. Urea is filtered in bowman's capsule, but not 100% so some secretion is involved . Here's a brief diagram in my notes, it doesn't cover everything tho
(Image removed from quote.)

Thank you so much! Could someone also help me out with this question please

[hannahhhh]

Thank you so much! Could someone also help me out with this question please

It would be B because they give you the tRNA so you have to go backwards twice to find the mRNA and then the original DNA:)

[sidzeman]

It would be B because they give you the tRNA so you have to go backwards twice to find the mRNA and then the original DNA:)

ahhhh that makes sense i misread the question and thought they meant mRNA woops!
I know this has been asked a million times but, what is the difference between hybridisation and selective breeding?

[hannahhhh]

ahhhh that makes sense i misread the question and thought they meant mRNA woops!
I know this has been asked a million times but, what is the difference between hybridisation and selective breeding?

In my notes i have something that says 'selective breeding techniques are reproductive technologies that may be used to achieve hybridisation'
and
Hybridisation is a process in which two genetically different strains of an organism are crossed to produce
offspring with more desirable characteristics than the parents
So I think artificial insemination and artificial pollination are the selective breeding techniques used to achieve hybridisation ? Not 100% sure but I think so

[mbdtHSC]

Hi I know this is rather late, but I’m really struggling to wrap my mind around interaction between T and B lymphocytes, cell mediated immunity and antibody mediated immunity - I don’t understand it extensively and I don’t really know how much I need to know of it anyway! I would forever appreciate any help at all!!!

This is basically what I've remembered:
Think of the immune response as centered around helper T-cells (the starting point)

Helper T-cells have surface receptor proteins that are specific to an antigen, meaning they are able to detect a specific antigen
The way  this detection can occur is by the helper T-cell recognising the antigen as it is displayed on MHCII molecules
MHCII molecules are glycoprotein molecules and are found on macrophages and B-cells, so either of these can hold the antigen on the surface of the MHCII molecule.

A macrophage can ingest an antigen and the fragments of the antigen are displayed on the MHCII molecule (can't think of a good analogy but maybe some jelly with the antigen fragments as sprinkles on top of jelly). So once the helper T-cell has the antigen brought by a B-cell or macrophage, its specific surface receptor protein will recognise the antigen and process it.

Then, the helper T-cell releases these 'signalling' chemicals called cytokines. The specific cytokine 'interleukin-2' basically stimulates B-cells to differentiate into PLASMA B-cells and MEMORY B-cells. T-cells also differentiate into CYTOTOXIC, MEMORY and SUPPRESSOR T-cells.

Plasma B-cells are important for the immune response as they can secrete antibodies, which specifically can inactivate or destroy the matching antigen.

Another mechanism comes into play for cytotoxic T-cells, which are MHCI molecules. These essentially mark infected body cells as targets for cytotoxic T-cells, which are ALSO specific to the antigen. The cytotoxic T-cells will move to find the infected cells, attach to them and release a chemical called 'perforin' which perforates the cell and causes it to lyse, which kills the infected cell.

Apart from this method of forming differentiated T and B cells, they can also be activated directly by antigens. Probably some stuff I missed, but if you know that in general you should be fine!

[hannahhhh]

This is basically what I've remembered:
Think of the immune response as centered around helper T-cells (the starting point)

Helper T-cells have surface receptor proteins that are specific to an antigen, meaning they are able to detect a specific antigen
The way  this detection can occur is by the helper T-cell recognising the antigen as it is displayed on MHCII molecules
MHCII molecules are glycoprotein molecules and are found on macrophages and B-cells, so either of these can hold the antigen on the surface of the MHCII molecule.

A macrophage can ingest an antigen and the fragments of the antigen are displayed on the MHCII molecule (can't think of a good analogy but maybe some jelly with the antigen fragments as sprinkles on top of jelly). So once the helper T-cell has the antigen brought by a B-cell or macrophage, its specific surface receptor protein will recognise the antigen and process it.

Then, the helper T-cell releases these 'signalling' chemicals called cytokines. The specific cytokine 'interleukin-2' basically stimulates B-cells to differentiate into PLASMA B-cells and MEMORY B-cells. T-cells also differentiate into CYTOTOXIC, MEMORY and SUPPRESSOR T-cells.

Plasma B-cells are important for the immune response as they can secrete antibodies, which specifically can inactivate or destroy the matching antigen.

Another mechanism comes into play for cytotoxic T-cells, which are MHCI molecules. These essentially mark infected body cells as targets for cytotoxic T-cells, which are ALSO specific to the antigen. The cytotoxic T-cells will move to find the infected cells, attach to them and release a chemical called 'perforin' which perforates the cell and causes it to lyse, which kills the infected cell.

Apart from this method of forming differentiated T and B cells, they can also be activated directly by antigens. Probably some stuff I missed, but if you know that in general you should be fine!

Thank you so so so much!! This makes 1000x more sense than anything else I’ve read!:)))

[sidzeman]

Could someone explain morgans work with sex linkage please? Also for the dotpoint about the collaboration and communication between franklin, watson etc. do you guys state overall communication was effective or that is wasn't?