VCE Biology Question Thread

[Quantum44]

Hi guys, so I had my first Bio SAC a few weeks ago, it was horrible, made many silly mistakes and walked out with a 30/50 (60%). My guess is that I sit around 6th in the cohort. I know my stuff and I do study, is the change of a 45 study score gone?

It really depends on the size and quality of your cohort although I'd say you can definitely improve if you are willing to work hard and work smart, one SAC isn't even worth that much anyway.

[Gogo14]

Hi guys, so I had my first Bio SAC a few weeks ago, it was horrible, made many silly mistakes and walked out with a 30/50 (60%). My guess is that I sit around 6th in the cohort. I know my stuff and I do study, is the change of a 45 study score gone?

Nup. Adding on to Quantum's advice,

That was me last year. Except I didnt rank 6, I ranked like 15th. I just tried my best and managed to pump out a 45. If i can do it, you definitely can

[Bri MT]

Hi guys, so I had my first Bio SAC a few weeks ago, it was horrible, made many silly mistakes and walked out with a 30/50 (60%). My guess is that I sit around 6th in the cohort. I know my stuff and I do study, is the chance of a 45 study score gone? I was on top of my year 11 cohort all year

There are so many variables involved in what your study score is, and while I don't know your cohort strength I find it highly unlikely that this one SAC will determine your future. Last year I got 60% on a biology SAC and was distraught, but I was still rank one and I ended up getting a study score of 47. For me, learning to slow myself down and doing lots of practice questions reduced my number of stupid mistakes, and I started catching them more often.

[cookiedream]

For the current 3/4 study design, do we need to know about plant hormones (auxin, etc) and junctions (occluding, etc) ?

[TheAspiringDoc]

For the current 3/4 study design, do we need to know about plant hormones (auxin, etc) and junctions (occluding, etc) ?

Yes I've heard it's  helpful to know plant growth regulators in slight detail. Technically they are in the SD.
Don't overcomplicate it though.
What's occluding? We skipped that!

[Quantum44]

For the current 3/4 study design, do we need to know about plant hormones (auxin, etc) and junctions (occluding, etc) ?

It's helpful to know a couple of things about the five main plant hormones (auxin, gibberellins, cytokinins, abscisic acid and ethylene) but the chances are you will never be tested on them on the exam as they are a very small part of the study design (although in early VCAA exams they come up a lot). For junctions I remember seeing them in the textbook last year but they were never taught and as far as I'm aware the study design hasn't suddenly included them, so I don't see any reason to learn about them for VCE biology.

[psychologie]

does anyone know if coenzymes are reusable? one book says they are but one says they arent!!

[cookiedream]

does anyone know if coenzymes are reusable? one book says they are but one says they arent!!

Coenzymes are reusable. Common coenzymes include ATP, NADH, and NADPH

[Molel Sunil]

Can anyone explain the electron transport chain to me in simpler words?

[Quantum44]

Can anyone explain the electron transport chain to me in simpler words?

NAD+ and FAD drop off electrons and protons --> electrons are passed along proteins embedded in the membrane --> this allows protons to be transported across the membrane --> Proton gradient is created --> Protons move through a special enzyme embedded in the membrane called ATP synthase --> as protons move through ATP synthase it drives the production of ATP --> Oxygen is the final electron acceptor

Note:
Proton = H+ ion

[TheAspiringDoc]

 
I can't actually believe I'm asking this - it seems so simple...
Anyway Edrolo is saying glycolysis and lactic acid fermentation produce water, while my textbook, ATARNotes and my teacher's notes don't mention it?
It's a bit worrying as this directly links to the study design, so hopefully someone could lear this up!
Thnky

[Arithmetic]

Yes I've heard it's  helpful to know plant growth regulators in slight detail. Technically they are in the SD.
Don't overcomplicate it though.
What's occluding? We skipped that!

Have you guys already begun cellular signals?! The teacher assigned it for us to do over the easter holidays and come back over them when we go back to school.

[zxcvbnm18]

What is the difference between a receptor cell and a target cell!

[CCleigh]

this is kind of a dumb question but im in the early stages of learning bio and what is the really necessary things u need to know about photosynthesis light dependent and independent reactions? everything seems so complicated and i wanna know what is really necessary but in a simpler format too, if that makes sense

[TheAspiringDoc]

this is kind of a dumb question but im in the early stages of learning bio and what is the really necessary things u need to know about photosynthesis light dependent and independent reactions? everything seems so complicated and i wanna know what is really necessary but in a simpler format too, if that makes sense

Here's a very basic overview of what you do in VCE bio:

Firstly, you have to describe the purpose of photosynthesis

Spoiler

basically just converting solar energy to chemical energy in glucose for later use in the plant

Then, you learn the overall balanced chemical equation

Spoiler

dont forget to say "in the presence of chlorophyll and light energy"

Then, you learn where photosynthesis happens

Spoiler

in different parts of the chloroplast in some plant cells (but not all - eg the roots!)
Note that chloroplasts contain  grana which in turn are made of thylakoids - which have pigments such as chlorophyll in their membranes
Chloroplasts also contain a fluid called "stroma" - which becomes important later
Also, you learn about how chloroplasts have their own circular DNA and ribosomes, and how they have two membranes around the entire chloroplast - all of which is evidence that chloroplasts have prokaryotic* origins!
*google for clarification 

Then, you learn about the stages of photosynthesis

Spoiler

-where each stage occurs in the chloroplast
-when each stage occurs (light dependent comes before light independent)
-the inputs and outputs of each stage

Finally, you learn the effect of different factors on photosynthetic rate

Spoiler

-carbon dioxide concentration (it is an input of photosynthesis)
-temperature (affects activity of photosynthetic enzymes)
-light intensity (needed for pigment excitation in the light dependent stage)
-light wavelength (basically, red is optimal, while green isn't so good)

I'm aware I have really explained the details of photosynthesis, so here's a little excerpt from Cosine's U3 Notes:

Spoiler

Light dependent:
-   The reactions occur in the grana (thylakoid membranes)
-   Light energy is absorbed from the sun light via chlorophyll
-   Water molecules split to form H+ ions and O2 gas. The O2 gas is released via the stomata. Excited electrons flow through the electron transport chain to provide energy for ATP synthesis
-   Unloaded electron acceptor molecules, NADP+, accept H+ ions to form NADPH

Inputs: H2O, ADP + Pi, NADP+
Outputs: O2, ATP, NADPH

Light independent:
-   Occur in the stroma of chloroplasts
-   In the Calvin cycle, CO2 and H+ ions (from the NADPH formed in the light dependent reactions) are used to synthesize sugars.
-   Energy is provided by the ATP molecules produced during the light dependent reactions

Inputs: CO2, ATP, NADPH
Outputs: Glucose, ADP+Pi, NADP+

Glucose is the main product of photosynthesis, however, other organic molecules are also produced:

-   Glucose and fats can be used as energy sources in the process of respiration
-   Cellulose is synthesized from glucose monomers to form the cell wall
-   Proteins have a myriad of functions within the cell.

Note: Oxygen is produced as a waste product of photosynthesis and is released from the chloroplast during the light dependent reactions.

By the way, all of this will make better sense when you've covered other topics (enzymes, biomolecules, cellular respiration) in detail.