Microorganisms live everywhere on Earth, but what are they and how do they affect humans? Life processes - Humans and other animals - Microorganisms Learning Points Microorganisms are so small they can only be seen with a microscope. Viruses, bacteria and fungi are all microorganisms. A Twig Curriculum Film. Delivering key learning points. Get straight to the facts in just three minutes – directly linked to core learning, Twig's curriculum films will fit neatly into your lesson plans.