I struggle with exam timing and as a result I always run out of time before finishing the paper. How can avoid this in the future?

This is a fairly common problem across many A level subjects but in my experience particularly amongst those taking biology papers. Whilst there are several strategies to counteract this, such as prioritising questions based upon how they are weighted for marks, or skipping past questions that you've been stuck on for more than two minuets allowing you to progress with the exam, with the majority of candidates time pressure arises as the simple result of writing to much for each question.  An example: Describe how microorganisms in the soil act to provide an absorbable form of Nitrogen for plants.   Now this question would typically be worth anywhere in the region for 4-6 marks and would typically have a half a page to a page to answer it. As such it may be tempting for the candidate to "spurge" everything they know relating to this topic into the space provided. Perhaps reflecting on the role of nitrates in amino acid synthesis or perhaps the role of nitrogen fixing bacteria in the roots of legumes. However, upon reflection this information is not requested by the question and as such is completely superfluous (note it specifically referees to micro organisms in the soil). in fact it is perfectly possible to obtain all the marks available in approximately 2 sentences. The first stating that saprophytic bacteria convert proteins contained in organic matter in the soil into ammonia (2 marks).Then go on to further describe hoe ammonia is converted to nitrite and then nitrate by nitrifying bacteria.(3 marks).  The key to succeeding in biology exams comes from understanding what key phrases and chunks of information that the question is asking of you and then going on to provide it as succinctly as possible.