1. How did you go about learning the content and how did you manage learning concepts that were within the study design? Of course, if we learn concepts outside of the study design, how does one manage to answer questions in a way that is still within the requirements.
I think how you should go about ensuring what you learn and then write about is actually relevant is going to depend a bit on the way your teacher teaches you. My teacher was very good at sticking to the study design and not giving us unnecessary information so I didn't really have to worry about whether things were relevant - if I was learning it in class then it was relevant. Definitely not the same for all teachers though.
I 100% recommend making your notes based on the study design. The bio study design is pretty clear in what it wants you to know (except for a few points, most of which are cleared up
here. So if you write down (or type if you're making online notes) the dot point of the study design at the top of the page and then write your notes below it, you can refer back to that dot point and make sure that you're only including things that you actually need to know. Most (probably all) textbooks have unnecessary information in them - some of that is there to provide context despite not being directly assessable but there's also normally stuff that just isn't relevant.
If you're writing something down and you're not sure it's relevant then look back at the study design. For example, something that came up often this year was how much detail you need to know about signalling molecules
study design
the sources and mode of transmission of various signalling molecules to their target cell, including plant and
animal hormones, neurotransmitters, cytokines and pheromones
VCAA's clarification of the study design
No specific molecules or physiological/other effects are required: the focus is on these molecules as initiating the process of signal transduction. Students should recognise that all of these are examples of signalling molecules and are produced in different locations and are transmitted in various ways.
So you can tell just from that it's very clear exactly what you need to know. If it's not mentioned at least implicitly in the study design then you don't need to know it. Generally the things that people tend to get confused on are things that were in the old study design and still appear in some text books. Whenever you move onto a new topic in class just keep checking back on the study design to make sure everything in your notes are things that you actually need to know.
re: Answering questions within the study design
This again comes back to knowing the study design very well. When I answer bio questions, I don't look at the question and go 'what do I know about this topic', I look at the question and go 'what does VCAA want me to talk about'. It becomes fairly obvious after you've done some questions that they're all actually fairly similar. The questions themselves can be very different, but they'll always be testing something from the study design and you've just got to figure out what they're trying to test, and then you'll know what it is they want you to talk about.
2. How can we understand VCAA's definitions and requirements (apart from examiner's reports and the study design)?
What do you mean by this? Like definitions for answering question? Imo knowing a perfect definition is overrated - probably useful for SACs, but generally in exams you're not going to get many definition questions (except multi choice) and when you do they tend to be presented with a scenario so you can't just write out a word for word answer anyway. I think this comes down to doing lots of VCAA questions so you learn what to expect from them and the way they ask things as well as being very familiar with the study design so you know what they're asking. If you're after definitions you can find Heidi's list of VCAA approved definitions
here however note that it is a few years old so there may be things on there that you no longer need to know.
3. How did you circumvent writing too much and ensuring that you were both concise and answered the question in its entirety? What strategies did you apply? For example, re-doing questions you got wrong, using dotpoints?
At this early stage I don't think you should be thinking about how to make your answers better, but rather how to answer them in the first place. A bit of this depends on what feels natural to you, you have to explain things in a way that makes sense to you. I think it helps to treat it like your explaining the answer to another bio student - you don't need to explain extra information because they already know that. You
just need to answer the part they're asking. To know this you also have to know what they're asking in the first place, which related to what I've said above. Use the most concise and direct language possible. Don't describe processes (unless that's what the question is asking), you can just name them. e.g. If you're given a 3 mark question on how DNA is converted into a product that leaves the cell, there's no need to describe the steps in detail, you just need to outline them. I guess what I'm saying is be aware of how much detail the question requires - this comes from the marking guide - and then answer the question as concisely as you can but within enough detail that it warrants however many marks are on offer.
I didn't find that redoing questions helped much for conciseness, I think it'd be more effective to go back to your answer and just cross out everything that you didn't need to include in the first place, it forces you to ask yourself 'do i need to write this' whereas if you're just rewriting it then you might just end up writing the same thing in fewer words - which is better, but if you don't need it at all then you want to try not to include it at all.
Dot points definitely can help. I didn't write actual dot points, but I did consciously use short, direct sentences with the same theory that it would help to only include the important points.
Something else that may help is re-reading the question after you've answered it - you may not always have time for this but when you do it can help. So read the question, answer it, and then re-read the question to make sure that you've actually answered every part of the question.
4. How did you go about getting in plenty of practice throughout the year, in respect to answering questions and retaining content in such a content heavy subject?
I found mindmaps and drawing diagrams and flowcharts etc. super helpful. It can feel like there's heaps of information but a lot of it is interconnected (e.g. you learn about phagocytosis as a type of endocytosis but then you later learn about phagocytosis in the immune system). Throughout the year I found it super useful to connect what I was learning to things I had previously learnt. I didn't actually do this on paper, but as I was learning it I was thinking about how it related to other things I've learnt (there's research to support that linking new information to information you already know is a very effective strategy for remembering new things). It also helps you recall the information you learnt previously because you're constantly thinking about how it links into what you're currently learning.
One of the most important things in relation to this is to make sure you're up to date throughout the entire year. If there's anything you're even slightly unsure of, find out about it then, don't wait for the end of the year and try to cram.
Definitely worth doing practice questions throughout the year - I'd avoid recent VCAA questions, but doing old VCAA questions throughout the year is definitely useful. Other sources of questions can be useful too, just be aware that they may not be entirely relevant anymore. Questions from your teacher are absolutely worth doing though because they're the ones who write your SACs.
I'm going to sound like I'm just plugging AN here lol but I'm going to do it anyway. One of the reasons I initially paid attention to the bio questions thread on here was because I wanted to know what other people were struggling with so that I could make sure that I knew it well, and I definitely think it's something worth paying attention to. You don't want to be making the same mistakes as everyone else, there will always be questions on the exam to separate people out so they're the questions you want to make sure that you're getting right. So pay attention to what people in your class or on here are struggling with, chances are they're the same topics that everyone is struggling with, and then make sure you know them really well.
re: retaining content
Make sure that you're regularly going back over the old content as well. Whether that be through doing a few questions, watching some youtube videos, or whatever it is. Make sure you're regularly revisiting it and not just going 'yep done that' and moving on.
Please do not worry if you feel that you did not do as well as you would have liked (I am sure it is the pressure we all feel during results time) as I would love to hear from past and current students. 
I know I've gone and written a really long thing here, but I really want to encourage everyone else to share their advice too. There isn't a right or wrong answer to any of these questions, so the more people's suggestions, the better
