I've spent a lot of time lately marking essays from my first-year students. For many of them, this may be the first essay they've written in a while, & along with getting their heads around the essay-writing process, they've also got to come to terms with the academic environment that they're working in. That means: making sure that they research the topic; read reasonably widely around the question they've chosen to work on (I always give a choice); make sure that as they write they cite the sources that they've used; include a properly-formatted References section; choose good-quality sources of information, & so on & so forth.
All that is probably a fairly daunting task if you're new to the game, so I try to give as much guidance & direction as possible. There's an outline of some of the key ideas i'll be looking for, for example. And we give a lot of instruction, in the Study Guide & in tutorials, on things like references, proper citations, how to paraphrase, together with the really basic stuff like double-spacing, wide left-hand margins (for marker's comments)...
Now, if you're given that sort of support, use it! Follow instructions! I have lost count of the number of times I've written 'please follow instructions' on these essays, but overall far too many people have lost marks that they didn't need to...
But going beyond that, it's also necessary to think carefully & critically about the question & how you're intending to answer it - the meaty stuff, that goes beyond issues of presentation. If you've been following this blog for a while, & you're preparing for Scholarship Biology at the end of the year, you might remember me saying that a common problem for schol candidates is a tendency to do a 'brain dump': to write down anything and everything that might seem remotely relevant to the topic. This doesn't do you any favours, because it does rather suggest that you haven't thought your answer through - and skills such as critical thinking & the ability to integrate information into a coherent whole are some of the attributes that the examiner is looking for in successful candidates.
To take one of my essay topics as an example (I'll blog about the science itself later on, cos it's really very cool and interesting stuff): the question was based on a research paper looking at the relationship between a species of marine crustacean called Santia and the algae that grow on the animal's exoskeleton. I asked my students to explain the nature fo the relationship and to discuss its advantages and disadvantages to the organisms involved.
Now, the relationship is essentially a symbiosis (where 2 different species live in close contact for part or all of their life cycles) or, more specifically, a mutualism, because there are advantages to both species. So the first thing I'm looking for is some definitions, and an explanation of why it's a mutualism. But you wouldn't include a whole lot of stuff on endosymbiosis & the origins of mitochondria & chloroplasts, for example, because that's not relevant to the question in the form I set. (I could have asked my students to place the Santia/algal relationship in the wider context of the evolution of symbioses, but that would be a whole different ballgame.)
Similarly, once you got into discussing the advantages/disadvantages, you should be focusing on the two organisms involved in this particular example. Yes, there are a lot of other symbioses around, and perhaps fewer mutualistic relationships, but I don't want to hear about those in a lot of detail. What you could do is point out that the whole symbiosis-mutualism thing isn't actually all that clear-cut, and whereSantia & its carapace-dwelling algae fit on the spectrum.
But you might well include material on what closely-related species do, because the relationship we're talking about is unique. How do other species of isopods & algae get by? What sets Santia apart? Attention to that sort of detail turns an otherwise OK essay into a very good one.
But it does require careful thought :-) So take the time to do that (yes, even in the pressure-filled context of a Scholarship exam!); it'll repay you in the end.