Which solution has the highest concentration of particles?
1 M calcium chloride
1 M sucrose
1.5 M glucose
0.5 M sodium chloride
The solution with the highest water potential is
0.1 M sucrose
0.4 M sucrose
0.2 M sucrose
0.6 M sucrose
glucose diffuses slowly through artificial phospholipid bilayers called?
simple diffusion
phagocytosis
active transport protein
facilitated diffusion
The presence of cholesterol in the plasma membrane of some animals
membranes more fluid when cell temperature drops
allows removal of hydrogen from saturated phospholipids
allows addition of hydrogen to unsaturated fats
membranes are flexible thus it can sustain greater
If a modern electron microscope (TEM) can resolve biological images to the nanometer level as opposed to the best light microscope this is due to which of the following?
the focal length of the electron microscope is significantly longer
contrast is enhanced by staining with atoms of heavy metal
electron beams have much shorter wavelengths than visible light
the electron microscope has much greater ratio of image size to real size
the electron microscope cannot image whole cells at one time
Which of the following correctly lists the order in which cellular components will be found in the pellet when homogenized cells are treated with increasingly rapid spins in a centrifuge?
ribosomes, nucleus, mitocondria
chloroplasts, ribosomes, vacuoles
nucleus, ribosomes, chloroplasts
vacuoles, ribosomes, nucleus
nucleus, mitocondria, ribosomes
In the fractionation of homogenized cells using centrifugation, the primary factor that determines whether a specific cellular component ends up in the supernatant or the pellet is
the relative solubility of the component
the size and weight of the component
the percentage of carbohydrates in the component
the number of enzymes in the fraction
the presence or absence of lipids in the component
A primary objective of cell fractionation is to
view the structure of cell membranes
identify the enzymes outside the organelles
determine the size of various organelles
separate the major organelles so that their particular functions can be determined
crack the cell wall so the cytoplasm contents can be released
The advantage of light microscopy over electron microscopy is that
light microscopy provides for a higher magnification than electron microscopy
light microscopy provides for higher resolving power than electron microscopy
light microscopy allows one to view dynamic processes in living cells
A and B
B and C
When biologists wish to study the internal ultrastructure of cells, they most likely would use
a light microscope
a scanning electron microscope
a transmission electron microscope
What kinds of molecules pass through a cell membrane most easily?
large and hydrophobic
large polar
small and hydrophobic
ionic
Water passes quickly through cell membranes because
the bilayer is hydrophilic
it is a small, polar, charged molecule
it moves through hydrophobic channels
it moves through aquaporins in the membrane
Chloride ion channels are membrane structures that include which of the following
gap junctions
hydrophilic proteins
aquaporins
carbohydrates
What would you expect to be a problem for someone with nonfunctional chloride channeling?
inadequate secretion of mucus in the lungs
buildup of excessive secretions such as the pancreas
buildup of excessive secretions in organs such as lungs
sweet that includes no mucus
celery stalks that are immersed in fresh water for several hours become stiff and hard thus...
hypotonic to both fresh water and the salt solution
hypertonic to fresh water but hypotonic to the salt solution
hypertonic to both fresh water and the salt solution
hypertonic to fresh water but hypertonic to the salt solution
water diffuses through
facilitated diffusion protein
active transport proteins
two answers are correct
