Study genetics, experiments, animals and grasses (and/or crops/soils) and you'd definitely get over a H7 as they are definite questions. Just do all the exam paper questions and learn off the answers, as they just repeat themselves every year
Flash cards; make them on the basics you need to pass by looking over the papers. Do them every single day, and tst yourself every week and see where youre struggling, and knuckle down on that topic/s. Best of luck.