Question

A transmission electron microscope would be the best microscope choice to study _______. a. structures smaller than cells b. single celled organisms c. plant leaves d. amphibian organs

Answer 1

The right answer is a. structures smaller than cells.

In the transmission electron microscope, electrons are emitted by heating a tungsten filament (or crystal of lanthanum hexaboride). These electrons are then accelerated with a voltage of between 200 and 1000 kV (1000 kV for the most expensive). Once the vacuum is in the cell, the electron beam is passed through a sample about 3 mm in diameter and less than 20 nanometers thick. Then this beam is focused with the help of magnetic lenses towards the screen or the photographic plate.

The operation of M.E.T is analogous to that of an optical microscope.

In light microscopy, a beam of photons is sent through a sample. This beam is then focused through optical lenses to the image plane of the lens. An enlarged image of the sample is observed.

Answer 2

Structures smaller than cells or Single celled organisms