These are only questions you can answer. Motivated students are willing to listen effectively. They listen to lectures with a receptive mind and with complete attention. They write everything down that is put on the board and they add notes about the instructor's emphasis and comments. Motivated students review their notes regularly and ask questions about things they don't understand.
Motivation comes primarily from within.
And the nice thing is that, when you are motivated, you almost always come to enjoy what you are doing. Prerequisites are based on the past experience and expectations of biology instructors. Of course, if your knowledge or skills from the pre-requisites are weak or a few years old, you may need to refresh yourself. If you have any questions, please ask me. College biology classes also require that you have college level reading and writing skills.