Final answer:
The asterisk in the context of a microscope would likely refer to a type of microscope, such as a 'compound microscope' or other terms related to microscopy. These devices magnify tiny organisms and cells for scientific study.
Step-by-step explanation:
The word that should replace the asterisk for microscope is likely to be related to its usage or a specific type of microscope, such as a 'compound microscope,' a 'light microscope,' or a 'transmission electron microscope.' These instruments magnify objects to allow scientists to study cells and other small entities that would otherwise be invisible to the eye. Microscopy is the practice of using microscopes to observe minute specimens. Microorganisms like bacteria and fungi are perfect examples where microscopes can be essential tools for observation. Typically, light microscopes are used to observe cells, with a human red blood cell measuring about eight micrometers in size as a reference for the scale of observation.
Moreover, the orientation of images viewed through a microscope is affected by its optics. The image seen through a microscope is inverted due to the manner in which light passes through the lenses. Therefore, when an object on a slide is moved in one direction, it appears to move in the opposite direction through the microscope's view. It's important to note that binocular or dissecting microscopes include additional systems that allow the final image to appear upright, counteracting the inverted view provided by traditional compound microscopes.