Microscopy and Cell Theory Review

Fill-in-the-blank flashcards reviewing microscope properties, types, parts, history of cell discovery, and fundamental principles of cell theory.

A microscope is an instrument used to see objects that are too small for the __________ eye.

naked

A good microscope should have at least three properties: good resolution, good contrast, and good __________.

magnification

__________ power refers to the ability to produce separate images of closely placed objects so that they can be distinguished as two separate entities.

Resolution

The resolution power of an unaided human eye is about __________.

$0.2\,mm$ ($200\,\mu m$)

While the resolution power of a light microscope is about $0.2\,\mu m$, the resolution power of an electron microscope is about __________.

$$0.5\,nm$$

Immersion oil enhances the resolution power of a microscope because it has a higher __________ index than air.

refractive

Contrast in microscopy is improved by __________ the specimen, which binds to the cells.

staining

In a light microscope, the four objective lenses are scanning ($4X$), low power ($10X$), high power ($40X$), and oil immersion (__________).

$$100X$$

The total magnification of a field viewed under an oil immersion objective ($100X$) with a $10X$ ocular lens is __________.

$$1000X$$

A bright field microscope forms a __________ image against a brighter background.

dark

The parts of a light microscope are divided into three groups: mechanical part, magnifying part, and __________ part.

illuminating

The __________ connects the ocular lens to the objective lens and holds the microscope.

C-shaped arm

The __________ is mounted beneath the stage and focuses a cone of light on the slide.

condenser

The light passing through the condenser is controlled by the __________ diaphragm.

iris

The five main parts of a Scanning Electron Microscope (SEM) are the electron gun, column, specimen chamber/stage, detector, and __________.

computer

To examine tumor cells under a TEM, ultrathin sections of approximately __________ thick are cut and stained with heavy metals.

$$70\,nm$$

Around the year 1590, Dutch lens makers Hans and Zacharias Janssen invented the first __________ microscope by putting two lenses together in a tube.

compound

In 1665, English scientist Robert Hooke coined the name "cells" after observing dead oak tree tissues in a piece of __________.

cork

Around 1683, Anton Van Leeuwenhoek observed living cells under a simple microscope and named these small organisms __________.

animalcules

In 1855, Prussian physician Rudolph Virchow proposed that new cells are formed only from __________ cells.

existing

According to cell theory, __________ generation of cells does not occur.

spontaneous

One square centimeter of human skin surface contains over __________ cells.

$$100,000$$

Modern electron microscopes like TEM and SEM can magnify specimens up to __________.

$$500,000X$$

One major disadvantage of using electron microscopes like TEM and SEM is that the specimens must be __________.

dead

Cells with a membrane-bound nucleus and membrane-bound organelles are categorized as __________.

eukaryotes

Prokaryotic cells, such as bacteria, lack a membrane-bound nucleus and membrane-bound organelles except for __________.

ribosomes

The three basic cell structures consist of the cell membrane, nucleus, and __________.

cytoplasm