Bear in mind the time pressure in exams - just writing more lengthy and detailed answers may not be best. You might need to revise more thoroughly but it's not just about your knowledge of the subject - try to consider issues such as your analysis of what the answer was asking for and whether each aspect of the question was fully considered, did you write enough?, were you concise?, did you use all the appropriate scientific terminology? etc

Are there any aspects from the tutorial or the exam question that you cannot recall effectively or don't fully understand - things you need to ask the teacher about or revise more thoroughly. Were there any questions prompts in the tutorial notes you're not sure about?