1. How exactly does allergen immunity therapy work? How come introducing small doses of allergen reduces immune system reaction but a vaccine leads to a great production of antibodies making it worse?
2. Is it better to day “structural morphocology” as is written on the study design or “comparative anatomy”. I put the former but debated whether to put the latter which was VCAA’s answer. Should I put both and one in brackets?
3. Also for question 7c in 15’ VCAA exam it’s asking how production of different proteins can happen despite it being the same hormone. VCAA said factors expressed by regulatory genes could lead to production of different proteins. I don’t understand this at all! I said it could activate different signal transduction pathways which my teacher said it’s correct!
Responses:
1. Allergen immunity therapy works by desensitising the body to allergens by periodically exposing a person to larger amounts of allergens. This reduces the immune reaction as the person is unlikely to come into contact with large doses of allergen naturally (hence the person is densitised). An allergic reaction is different from a immune response produced by a person, an allergic reaction is stimulated by the presence of an allergen --> which is harmless in the majority of other people, whereas a pathogen that causes an immune response is potentially harmful to all and most may not have immunity against a specific pathogen. Hence, this is where vaccines come in, before a pathogen has a chance to infect you, you are injected with a vaccine to build immunity (memory B cells, antibodies, etc) so that in the future if you are ever exposed your body will be able to react in time to prevent an infection.
2. I reckon both works as both describes the same idea, btw "morphology" spelling.
3. For this question, GC is a hormone that binds to an intracellular receptor to act as a transcription factor. Different signal transduction pathways usually refer to when a hydrophilic molecule binds to an extracellular receptor and different secondary messenger molecules and different cascade of events occur. So their answer does make sense, the factors expressed by regulatory genes are repressor proteins that controls which genes are switched on and off. Imo when they say "given that the genetic sequence is identical" you must refer to this, hence why answers related to post-transcriptional and post-translational modifications were not accepted or different signal transduction pathways. Btw: the average for this question was 0.1 for a 2 mark question