When asked about what they loved or found challenging in the VCE Biology course, most Connecties agree that Immunology – of Unit 3 AOS 2 – fits in both categories. The scope and depth of this topic, and the level of detail assessors want to see on the page, definitely makes mastering it a big ask.
With that said, understanding how all the complex moving parts fit together is incredibly rewarding, not just in terms of your SAC marks, but also because it will give you a great head start on university level Biology.
In this article, we’ll unpack the commonly examined immunology topics in SACs and exams, highlight often-neglected (but important) things to know, and help you test your knowledge with targeted comprehension questions. Of course, this is only a guide – your teacher’s advice and the VCE Biology study design are extremely valuable sources of information – but we hope that our first-hand student experience can give you a hand, too.
Usually, pathogen-related content is examined in the form of rapid-fire, recall-based multiple choice questions, or as the first few parts of an extended response question leading up to a description of adaptive immune responses.
Also be prepared to link pathogen-related content to more complex immunological processes.
It’s definitely important to know your comparisons between innate and adaptive immunity.
Understanding the difference between, and being able to list components of, first (fixed barriers) and second (activating in response to an infection or injury) lines of innate immune defence is crucial. This is usually assessed via multiple choice questions, but a multi-part short answer question could easily ask you to identify an innate immune barrier for one mark, and describe how it protects the body from infection for another.
These are the big ‘processs’ of the innate immune system (whereas the ‘processes’ for the adaptive immune system are hypersensitivities, humoral and cell mediated responses).
Phagocytosis – the process by which phagocytes ingest and destroy pathogens – is a crucial process of innate immunity, while the inflammatory response is really what ties all the different elements of the innate immune system together into one interactive order of events.
Finally, don’t forget that cytokines are the messengers used by the innate immune system to communicate. An exam-style question integrating different topics of Unit 3 might ask you to link the mode of action of cytokines – a protein-based signalling molecule – to the signal transduction pathways you learned about earlier in Unit 3 AOS 2.
Antigens and antibodies have a very special structural relatioship: antigens are complementary and specific to the antigen binding sites of antibodies. VCAA-style questions really hone in on this: a fairly common multiple choice question will ask you to choose the antibody that matches the shape of an antigen shown on the surface of a pathogen.
You should also be confident with drawing the quaternary structure of antibodies.
Antigens are molecules on the surface of pathogens that the immune system recognises and responds to. Make sure you are able to distinguish them from allergens, which are innocuous (non-harmful) molecules from the environment that provoke an excessive immune response called an allergic reaction.
Having a general understanding of what antibodies do definitely comes in handy too, especially in relation to the adaptive humoral response.
The chance that a detailed short answer question about either the humoral or the cell mediated response will pop up is quite high. And for good reason: getting a solid grasp on this part of the topic is definitely tough, and really helps teachers and examiners identify top-performing students.
While often taught as two completely separate processes, try learning humoral and cell mediated responses as two branches of the same response, beginning with the activation of a T cell by an antigen presenting cell. That way, you’ll be able to reduce the amount of information you’re trying to memorise for each process, and gain a better understanding about the similarities and contrasts of each one. Our definitive immunology guide explains and illustrates this to a T.
Immunological memory is the mechanism behind vaccines, and the reason why after we get chicken pox once we rarely get it again. It’s a unique property of the adaptive immune response and often gets a spot on the end of year exam, either in the multiple choice or short answer sections.
Given the incredible complexity of the immune system, we can’t always expect it to work perfectly. Allergies and autoimmunity are the result of an inappropriately activated immune system, while immunodeficiency results when the immune system isn’t giving it 100%.
Often, the best way to learn about normal human function is to learn about what happens when things go wrong. So think about these immune disorders as specific case studies of the immune system’s importance and the function of certain immune components.
With these guidelines in mind, you can now clearly identify the parts of the topic you’re confident with, and the parts that you feel are more challenging. If you found answering some of the comprehension questions mentioned challenging, our definitive guide to immunology is for you. Here, we dive into the more challenging parts of the content, with detailed written explanations and original diagrams to deepen your understanding.
Without a doubt, immunology was my favourite part of the VCE Biology course. And with a now solid grasp of both the content and how the content is examined, it will fast become yours too.