Hi, Make sure the introduction directly addresses the key words in the question. Define them first them state the link/explanation. Conclusions are only really necessary for “Evaluate” questions in which you need a summary.
The key is in the wording of the question, if the question is asking you to explain/describe studies related to a concept, make sure the main paragraph/s focus on the details of the studies. If the question asks about the concept, the bulk of the essay should be about this with reference to studies. Don’t just write everything you know, keep it focused.