the ordinary light microscope is called a bright-field microscope because 1. the object appears light on a dark background 2. the object appears dark on a light backgroundi found the answer myself and it was #1.

The correct answer is option 2-the object appears dark on a light background.

Explanation:

Bright-field microscopy is the elementary or simple form of microscope used with compound microscopes. This is called a "brightfield" microscope because the specimen appears dark and contrasted in the bright light field.

For this specimen is placed on the stage of the microscope light source is then focused at the specimen. The condenser focuses the light on the specimen with the help of an aperture diaphragm. Light passes through the specimen which is collected by an objective lens which magnifies the light and transmits it to an eyepiece and to user's eyes. Some light is absorbed by dense areas, stains and pigments making specimen appear dark in bright light.

Thus, option 2-the object appears dark on a light is the correct answer.

not sure if this is what you'r looking for eubacteria and archaebacteria

the circled areas are referred to   as sunspots.   the sunspots are cooler than the   surrounding area.

sunspots are temporary phenomena on the photosphere of the sun that appear visibly as dark spots compared to surrounding regions. they correspond to concentrations of magnetic field flux that inhibit convection and result in reduced surface temperature compared to the surrounding photosphere.