A compound microscope is a really important tool in biology. It helps scientists study cell structures by making tiny things look bigger so we can see them. You can't see these small objects with just your eyes.

A compound microscope usually has two or more lenses working together. These are the objective lens and the eyepiece. They help to magnify, or enlarge, the details of what we are looking at.

Magnification and Resolution:

• To figure out how much a compound microscope can magnify an object, you can use this simple math:

  Total Magnification = Eyepiece Magnification × Objective Magnification

• For example, if the eyepiece magnifies 10 times (10x) and the objective lenses can be from 4x to 100x, then the total magnification can be from 40x to 1000x or even more!

Light Path:

1. Light Source: Light shines through the specimen we want to view.
2. Objective Lens: This lens collects the light and focuses it to create a bigger image.
3. Eyepiece Lens: This lens makes the image even bigger so we can see it clearly.

Image Formation:

• The microscope is so powerful that it can show details that are as small as 200 nanometers. That’s 200 times smaller than the light we can see!
• With this ability, scientists can look at important parts of cells, like the nucleus (which holds the cell’s DNA), mitochondria (the cell's energy factories), and the cell membrane (which surrounds the cell).

Applications:

• Scientists and students use compound microscopes a lot in labs for research and in schools for science classes.
• Around 80% of the work done in studying cells involves using microscopes.

To sum it all up, compound microscopes help us understand cell structures much better. They do this thanks to their great ability to magnify and show fine details.