I have been studying biology since I can remember and I am very pleased to very soon finish a PhD (Doctorate) in Biochemistry from Imperial College London. I have been teaching some students and most of them are very smart but tend to find Biology difficult.
Based on my experience I have put together the 3 pillars of studying Biology.
3. Answer Practice Questions.
Biology is like a language. Hence, I always tell my students " You need to understand all those new keywords, which most of the time is not used in your everyday language". They literally keep a biology keyword book for new biology words.
Once my students understand the keywords and key points of the topic, all they have to do next is memorize this material. However, this step becomes very easy as their understanding of the subject will allow them to remember it.
The final step is practice, practice, practice. I always say the difference between an A student and a B student is answering practice question. This step validates the first two steps of understanding and memorizing.
Hence, see biology as a new language and learn it as such. Understand, memorize and answer a lot of practice questions. There is no easier way to get your A in Biology