Homework #2

As the magnification of a series of objective lenses increases, the working distance

decreases

If immersion oil was replaced with water, what would happen?

the refractive index of water would be greater than air but less than oil, improving resolution less than oil. (1. There would be no difference, 2. The refractive index would increase, improving resolution, 3. The refractive index of water would be less than that of air, decreasing resolution.)

Cell walls of most Archaea and bacteria contain peptidoglycan.

false (wikipedia: The cell wall of archaea is composed of S-layers and lack peptidoglycan molecules with the exception of methanobacteria who have pseudopeptidoglycan in their cell wall.)

As the resolution (detail of an image) of a microscope system improves, the size of the smallest object that can be seen clearly

is not affected (is larger, is smaller, is not affected)

A cocci with the same volume as a rod has a ____________ S/V ratio than does the rod.

less efficient (a rod with the same volume as a cocci clearly has a higher S/V ratio because it is more spread out (longer). so a rod has greater nutrient flux than a cocci of the same size.)

A rod with the same S/V ratio as a cocci can have ____________ uptake across its cytoplasmic membrane than the cocci.

more efficient (a rod with the same volume as a cocci clearly has a higher S/V ratio because it is more spread out (longer). so a rod has greater nutrient flux than a cocci of the same size.)

A new protein has been described that transports a growth factor across the plasma membrane. This protein is most likely a/an:

Integral membrane protein (options: peripheral membrane protein facing outward, peripheral membrane protein facing the cytoplasm side, and cytoplasmic protein).

30× objective and a 20× ocular produce a total magnification of

600×.

Predict how the plasma membrane fatty acid composition would change as the temperature of the habitat of an aquatic bacterial species warms from 2oC to 15oC during the spring and summer months.

The percentage of saturated fatty acids would increase. (a. The percentage of saturated fatty acids would increase. b. The percentage of unsaturated fatty acids would increase. c. The percentage of saturated fatty acids would decrease.)

A feature unique to some archaeal plasma membranes is that they may

contains a lipid monolayer (1. consist of a lipid bilayer that lacks integral membrane proteins., 2. consist of a lipid bilayer with embedded proteins., 3. contain sterols such as cholesterol.)

In bacteria, as the surface area-to-volume ratio increases, nutrient uptake becomes

higher

Epulopiscium fishelsoni has a ____________ plasma membrane to increase its S/V ratio to compensate for its large size.

highly convoluted

Resolution(image detail) improves when the wavelength(distance between successive crests of a wave) of the illuminating light decreases.

true