Most likely, you have multiple finals coming up and you want to make sure you have enough time to study effectively for all of them. Draw up your study plan and give yourself plenty of time to study for biology. If you're already a little bit behind and only have a few days to study, you can condense the study plan into a few days or even hours. Study the major topics you know will be on the test first. Also, study the concepts you have had trouble with and briefly review the concepts you know pretty well right before the final. To start your study plan, you need to figure out when you have free time to actually study. Grab a calendar and fill in all of your activities for the two weeks before your finals. Studying is the most effective in 20-30 minute chunks of time, so schedule study sessions of this length. Color code the activities on your schedule. Have separate colors for classes, appointments, meetings, leisure time, and study time. The best case scenario is to study a little bit each day, but if you don't have that much time, you'll have to study for larger amounts of time in fewer days. Making a list of topics is a great way to prioritize what you need to study so you're not spending time reviewing unnecessary information. If your teacher gave you a review packet, use this as a guide on what to study. You can also start by listing the chapter titles that were covered. Some topics you are likely to see on your exam include: DNA and RNA replication Protein synthesis Punnett Squares and genetic inheritance patterns Scientific theories of origin and evolution of species Levels of organization for organisms General structure, function, and biology of cells Stages of the cell cycle Using the calendar that has blocked-out study time on it, assign topics to these chunks of time. Focus on the concepts you know will appear on the test and the ones that you had difficulty in. Leave the two days before the test for review. Don't forget to schedule down time. Studying takes a lot of effort and energy. Breaks are essential so you don't burn out. Schedule time for exercise and/or fun. Try to schedule your study time for when you have the most energy. If you're a morning person, get up earlier and study. If you're not a morning person, don't force yourself to get up earlier to study. Same goes for being a night owl. Remember, if you only have a few days, you'll have to cover more topics in a day and you might not have time to get to everything. Some topics may take you less time to study, while others will take you more. Make sure you set aside extra time for concepts that you know you have struggled with. Giving yourself more time will allow you to really conquer that topic. If a topic ends up taking less time, move on to the next topic. Don't stop studying early just because something didn't take as long. You might end up needing that time later for a topic that you didn't think would take as long to study as it did. It's easy to skip a day and say you'll catch up tomorrow. But when tomorrow comes, you're not going to want to do the extra work. Your study schedule will only work if you stick to it. Try setting an alarm on your phone to remind you that it's time to study. Plan to do something fun or give yourself a small reward when you've finished your study block for the day.

Summary:
Start studying at least two weeks before the final. Create a schedule of all your current activities. Make a list of all the topics you need to study. Assign specific topics to focus on each day of the week. Set aside more time for difficult concepts. Stick to your schedule.