There are a number of internet sources where you can find good quality, copyright free images, charts, tables and figures to use in your assignments and other academic work. The ones below should be particularly relevant to students from the Science Faculty.
Wellcome Collection
Find thousands of Creative Commons licensed images from historical library materials and museum objects to contemporary digital photographs.

Glaciers. Coloured wood engraving by C. Whymper. Credit: Wellcome Collection. CC BY
Biodiversity Heritage Library
The Biodiversity Heritage Library contains text and image records on a wide range of topics in the life sciences. The Biodiversity Heritage Library Flickr pages includes some excellent images.
Geograph Britain and Ireland
The Geograph Britain and Ireland project aims to collect geographically representative photographs and information for every square kilometre of Great Britain and Ireland, available under Creative Commons licence.
Anatomy and Physiology Image Bank
This collection of images is from The Sourcebook of Medical Illustration (The Parthenon Publishing Group, P. Cull, ed., 1989). The images are “copyright-free as long as they are used for educational purposes.”
World Register of Marine Species
As well as an authoritative and comprehensive list of names of marine organisms, the World Register of Marine Species (WoRMS) provides images of marine life. Images are by default open-access under the terms of the CC BY-NC-SA license, unless stated otherwise.

Common Tern (Sterna hirundo) by Vitaly Giragosov. Licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License.
General Image Collections
See here for a list of free image libraries covering all subjects