Bad biology teacher Watch
Therefore your only route is to either approach middle or senior management However before you approach either of these people - because when you do so - you are making a formal complaint with all the implications that involves including to your class teacher
Before you do so you need to collect evidence that supports your claim. The organisation of the Biology curriculum you are undergoing is one piece of evidence. The opinion of your fellow pupils is another kind of evidence. What you must not do is to make your claim without evidence to back yourself up. That will reflect on you.
However - and assuming you are right in what you have said - you must demand your rights to be properly taught. Hopefully your PT will help you and certainly your HT should help. But before you approach either you must have collected your evidence. You will loose if it results in your word against your teacher and no evidence to support you..
So first - before you make any complaint - collect your evidence. Evidence is difficult to overlook or dismiss. It is also helpful if it is more than you who are complaining. I believe once you are organised your problem will be corrected within school. However a noise created outside the school about something going on inside the school - usually generates an immediate effect.
So. First get your evidence together - including other pupils who might also want to support you. What is evidence? Examples of lessons taught - jotters - teacher issued class notes etc. compared to what the SQA curriculum states should be taught. And there lies your case. It is not so much what you have been taught BUT what the SQA demands WHAT you should be taught and that rate by which you are being taught. Using the SQA to support you is no bad idea. Meanwhile do not disrupt or cause attention to be focused on you. You quietly collect your evidence. It might be best - since this will be a formal complaint (and you need to bare that in mind) - to go first to HT rather tan PT.
But that is for you to decide.
That sucks, and honestly you are just gonna have to most likely suck it up and use as many online resources such as Scholar, youtube videos, as many past papers as possible, just keep doing questions. Use the sqa course spec. Honestly Nat 5 Bio isn't too bad with problem solving so just try and learn all the content and you will be fine, you don't have to necesarilly understand the content to get a good mark in the exam.