The cellular level of organization. A detailed study of the cell in what year? This is a (blank) concept in biology
1830’s; unifying
Detailed studies of the cell originated from the works of biologists (blank) and (blank) in what years?
Schleiden and Schwann in 1838-1839
In the cell theory, what two scientists came up the concept that organisms are composed of cells? (country, type of scientist)
German botanist; Matthias Schneiden
German zoologist Theodor Schwann
In the cell theory, what scientist came up with the concept all cells come only from preexisting cells because
cells are self-reproducing? (country, type of scientist)
German physician Rudolph Virchow
Cells range in size from what to what in diameter?
one millimeter (mm) down to one micrometer (μm) in diameter.
Cells need a large surface area of plasma membrane to
to adequately exchange materials.
What does the surface-area-to-volume ratio require?
that cells be small
What is the surface-area-to-volume ratio in large cells?
surface area relative to volume decreases which also decreases the efficiency of transporting materials in and out of the cell
What is the surface-area-to-volume ratio in small cells?
Small cells – larger surface-area-to-volume ratio is advantageous for exchanging molecules
How do we see through a compound light microscope?
Light is passed through the specimen. Then it is focused by a series of glass lenses. It forms an image on the human retina.
In a compound light microscope, the maximum magnification is about
1000X
The compound light microscope resolves objects separated by (blank) μm,. How much better is this than the human eye?
0.2, 500X better than the human eye (Assuming the resolving power of the human eye is 1.0)
How do we see through a Transmission Electron Microscope? (3 steps)
What provides greater magnification, a compound light microscope or a TEM microscope?
TEM
TEM microscope resolves objects separated by (blank) μm,. How much better is this than the human eye?
0.0002, 100,000X better than human eye.
How do we see through a Scanning Electron Microscope? 6 steps
Magnification is the ratio between?
the size of an image and its actual size.
Resolution in a microscope?
the minimum distance between two objects that allows them to be seen as two separate objects.
Contrast in a microscope?
the difference in shading of an object compared to its background.
(blank) can be bent (refracted) and focused as they pass through glass, but (blank) can’t
light rays; electrons
How are electrons seen through the glass in a microscope? 2 steps
How does confocal microscopy work? 5 steps
How does Video-Enhanced Contrast Microscopy work? 4 steps
Prokaryotic lack a what?
membrane bound nucleus