The interviewer would like you to describe your short-term and long-term goals here. The scientific field is very competitive, and employers are looking for candidates that show an interest in longevity with the company. If you have goals of moving into a higher-level position, this is when you should elaborate on that. If you are interested in being part of a specific research or experimental project, you could mention that here as well. Avoid giving brief answers, such as 'I am looking to grow within a company.' Go into detail about the goals that you have and why they are your goals.