This is only from what I've heard, but sociology isn't nowhere near as respected as biology.
I'd expect this response from most people on TSR as well.
Biology is difficult, mainly in the way to approach it, but you should be fine. The content is mostly very enjoyable, can get tedious though at times, but still very interesting stuff nonetheless.
Do what you want, if you think your sociology teacher is going to jeopardise your grade in that subject, either change teacher, or change subject.
Biology AQA include:
BIO1
- microscopy
- cell organelles, prokaryotes & eukaryotes
- cell membrane (very nice topic)
- proteins
- carbohydrates
- lipids
- pathogens
- lung structure & function
- heart structure & function
- immunology (god damn interesting stuff, but there's a few bits e.g. about monoclonal antibodies, but with a few PPQs, easy & predictable)
BIO2
- differentiation, tissues, organs, organ systems
- plants - xylem & phloem (amazing topic)
- haemoglobin
- surface area to volume ratio
- fishies (transport mediums, like gills etc.)
- insects (transport mediums, via e.g. tiny pores called spiracles)
- classification (detestable, in that it's boring, but workload, meh.)
Practical
There might be one or two things missing, but those are the topics.
Yes there's a lot of topics, but again, it's worth it; very interesting stuff.
Just revise, and go back to it when necessary, or you will forget it. technically just review what you've learnt every so often.
I don't know about sociology, because I never took it, and haven't at all checked out the syllabus etc. etc.