Biology 2.02

Which is used to view the internal structures of cells?

TEM

When was the first microscope introduced?

The first microscope was first introduced in the 17th century.

What are the two types of electron microscopes?

Transmission electron microscopes and Scanning electron microscopes

Who named the cell, and how did he come up with that name?

"Cells" were names after the rows of small rooms found in a monastery.

What is a disadvantage of electron microscopes?

A disadvantage of electron microscopes is that they cannot be used to view living specimens because the methods used to prepare them for viewing kill the cells.

What are all living organisms composed of?

All living organisms are composed of cells.

Which is a true statement about microscopes? A. Dissecting microscopes are more powerful than compound light microscopes. B. Scanning electron microscopes are good for viewing living cells. C. Compound light microscopes pass a beam of light through a specimen and focus the beam of light on a screen to produce an image. D. Electron microscopes have a greater resolution than light microscopes.

C

A class collected water samples from a nearby pond and wants to observe the samples for microorganisms. Which microscope would be the most appropriate for the students to use? A. Dissecting microscope B.

Compound light microscope C. Transmission electron microscope D. Scanning electron microscope

Describe the compound light microscope. What types of specimen can be viewed?

Compound light microscopes are the most commonly used light microscope. They can be found in most science classrooms and biology laboratories. The light source is below the stage, and the light shines up through the thin specimen and then through the magnification lenses. Compound light microscopes can be used to view tissue samples, blood, microorganisms in pond water, microscopic cells, and some of the larger details within the cells.

Describe the dissecting microscope. What types of specimen can be seen?

Dissecting microscope is one type of light microscope. It is used for examining organisms at relatively low power, magnifying the image up to 40 times the size of the specimen. The dissecting microscope is useful for examining organs and tissue during a dissection. You can also use it to view the surfaces and details of leaves, stems, mold, spores, or other small objects that can be seen with the naked eye but require magnification in order to be examined closely.

What source do electron microscopes use to view specimens?

Electron microscopes use beams of electrons, instead of light, to view specimens.

What is magnification?

Magnification is how much larger an object appears compared to its real size.

What invention allowed scientists to learn more about cells and therefore life, in general?

Microscopes allowed scientists to learn more about cells and therefore life, in general.

What is resolution?

Resolving power is a measure of the clarity of the object

Which type of electron microscope is used to view the surface of a specimen in great detail?

SEM