What is 'magnification'?

What is bio-magnification ?

There is an object infront of convex mirror at a distance of 5 cm. If its focal length is 10 cm then What is its magnification ?

Assume that an object is kept at a distance of 20 cm in front of a concave mirror. If its focal length is 30 cm then What is the magnification of mirror in this case ?

A card sheet divided into squares each of size "1 mm"^(2) is being viewed at a distance of 9 cm through a magnifying glass (a converging lens of focal length 9 cm) held close to the eye. a) What is the magnification in produced by the lens? How much is the area of each square in the virtual image ?

The focal length of the objective and eyepiece of a compound microscope are 4 cm and 6 cm respectively. If an object is placed at a distance of 6cm from the objective, what is the magnification produced by the microscope ?

Magnification m =