Questão 1
Questão
Which solution has the highest concentration of particles?
Responda
-
1 M calcium chloride
-
1 M sucrose
-
1.5 M glucose
-
0.5 M sodium chloride
Questão 2
Questão
The solution with the highest water potential is
Responda
-
0.1 M sucrose
-
0.4 M sucrose
-
0.2 M sucrose
-
0.6 M sucrose
Questão 3
Questão
glucose diffuses slowly through artificial phospholipid bilayers called?
Responda
-
simple diffusion
-
phagocytosis
-
active transport protein
-
facilitated diffusion
Questão 4
Questão
The presence of cholesterol in the plasma membrane of some animals
Responda
-
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
Questão 5
Questão
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?
Responda
-
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
Questão 6
Questão
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?
Responda
-
ribosomes, nucleus, mitocondria
-
chloroplasts, ribosomes, vacuoles
-
nucleus, ribosomes, chloroplasts
-
vacuoles, ribosomes, nucleus
-
nucleus, mitocondria, ribosomes
Questão 7
Questão
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
Responda
-
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
Questão 8
Questão
A primary objective of cell fractionation is to
Responda
-
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
Questão 9
Questão
The advantage of light microscopy over electron microscopy is that
Responda
-
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
Questão 10
Questão
When biologists wish to study the internal ultrastructure of cells, they most likely would use
Questão 11
Questão
What kinds of molecules pass through a cell membrane most easily?
Responda
-
large and hydrophobic
-
large polar
-
small and hydrophobic
-
ionic
Questão 12
Questão
Water passes quickly through cell membranes because
Responda
-
the bilayer is hydrophilic
-
it is a small, polar, charged molecule
-
it moves through hydrophobic channels
-
it moves through aquaporins in the membrane
Questão 13
Questão
Chloride ion channels are membrane structures that include which of the following
Responda
-
gap junctions
-
hydrophilic proteins
-
aquaporins
-
carbohydrates
Questão 14
Questão
What would you expect to be a problem for someone with nonfunctional chloride channeling?
Responda
-
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
Questão 15
Questão
celery stalks that are immersed in fresh water for several hours become stiff and hard thus...
Responda
-
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
Questão 16
Questão
water diffuses through