How to Write a Biology Dissertation

A biology dissertation is a document designed to demonstrate a candidate’s ability to investigate, document, analyse and present the findings of a biological investigation. The final report, or dissertation, must be written in a coherent and logical manner with all arguments backed up by valid findings from the author’s own work, or by reference to other, peer reviewed, academic publications. In general, biology dissertations are laid out in various chapters using the following headings:

• Introduction
• Literature Review
• Methodology
• Results
• Discussion

The purpose of the Introduction to a biology dissertation is to set the context for the research, drawing together existing information from published sources, and information about the chosen research site or organisms, and should end by posing the “research question”, or hypothesis, of the biology dissertation. A Literature Review is not always a required component of a biology dissertation, but is, as the title suggests, a more in depth investigation of the available published material than would be used in the Introduction. A thorough Methodology is perhaps the most important chapter of any biology dissertation, as this is the section in which the author explains exactly how the scientific aspect of the investigation was conducted, along with justification of the choices of methods used. The Methodology should also include a detailed account of how the resulting data was analysed. In order to be accepted as a valid piece of research, the Methodology of a biology dissertation should be so clear that another researcher can read it and then exactly replicate the investigation. The Results chapter of the biology dissertation is simply an uncluttered presentation of the results of the analysis of the data, along with any relevant statistical representations of the raw data. Opinions and speculations concerning the results do not belong in this section, however, rather in the following Discussion. It is in this final section of the biology dissertation that the findings of the investigation are discussed in context with the available scientific literature, and possible reasons for observed events are proposed. It is also important to remember the hypothesis posed earlier in the biology dissertation; here in the Discussion it can be either accepted or rejected based on the interpretation of the results.

It is not uncommon for biology dissertations to include a few more sections than the key chapters described above. Before the Introduction an Abstract of around 300 words is often used to summarize the whole biology dissertation, focussing on the rationale behind the research, key results, and a summary of conclusions. After the Discussion there should always be a thorough Bibliography which lists all other works referenced throughout the text. The authors of biology dissertations also frequently include a small Acknowledgements section to thank anyone who has been helpful during the investigation or subsequent report production. As mentioned previously, the Literature Review is not always required in biology dissertations but in practice it can be a very helpful tool, as it gives a much wider and more thorough understanding of the subject in question, and also provides key facts and references in a readily accessible format, both of which greatly ease the production of the final biology dissertation. Another way to make writing the biology dissertation easier is to write the Methodology as it happens, and to input and analyze data as it is collected rather than waiting until the whole investigation is completed. This allows early detection of any problems with data collection or experimental procedures, meaning these problems can be remedied before the whole biology dissertation is jeopardised. Another fact worth remembering is that biology dissertations often study very variable systems, and so it can be very difficult to categorically prove a hypothesis. Instead, it can hep to try to aim to disprove a null (negative) hypothesis; for example, in a biology dissertation investigating dogs’ food preferences, offering dogs rice, bread, dog biscuits and fruit:

Hypothesis – Dogs prefer biscuits (most likely, but it could be that they choose bread just as often – i.e., hypothesis can’t be proved)

Null hypothesis – Dogs have no food preference (Much easier to disprove, as few would choose fruit, meaning the biology dissertation “works”)

The findings presented in a biology dissertation must be easily accessible to a reader, and so only analyzed and prepared data should be included in the Results chapter. Going back to the dog feeding experiment, raw data listing each dog’s name and breed and anything else should go into an Appendix at the very end of the biology dissertation. What is actually important is to know how many dogs chose each food type, and so a simple graph can be used to summarize the data and present it in a visually accessible format. All tables, graphs and images included in a biology dissertation should be labelled and titled well enough that a reader can interpret them without having to read the main text body. For example:

Following such a graph it is important for the author of a biology dissertation to include the results of statistical analyses, to inform the reader whether the apparent differences are actually statistically significant or not. The reasons for the observed differences, supported up by referencing other published material, would make up the bulk of the biology dissertation’s Discussion which should end with a few conclusions about the findings and overall effectiveness of the investigation, and any scope for future work. There are a number of different referencing styles used in biology dissertations, but probably the most common is known as “Harvard referencing” in which a statement is immediately backed up by its author and year, with the full reference, including journal name, issue number and page, listed alphabetically in the Bibliography; for example:

“…springs and hand-dug wells account for significant water usage (Becker and Zeitouni, 1998)….”

would be shown in the Bibliography of a biology dissertation as:

Becker, N. and Zeitouni, N., 1998. A market solution for the Israeli-Palestinian water dispute. Water International. 23(4): 234-243

There are no rules concerning how many sources should be included in a biology dissertation, but it is generally accepted that a good author will use at least 60 in a biology dissertation of between 7,000 and 10,000 words.