Any Lancaster Uni Natural Science students able to answer my query?

Hi. Yesterday, I attended the Offer Holder Day for Nat Science at Lancaster. I'm considering the Biology/Earth Science pathway. Unfortunately, the proper tour/demo for Biology was cancelled ( I don't know why), but a Lecturer was available to show us around at the end. While talking to him, he made it very clear that Year 3 Nat Sci undergraduates studying BSc would NOT be able to do a dissertation. Having looked again at the course literature since getting home, it definitely says that a dissertation is an option in the third year. The Lecturer seemed to imply that there just weren't enough supervisors to enable it to happen for Nat Sci students who could do a literature review instead. Please could you give me an honest answer regarding this as a dissertation is really important to me.