What limits the resolving power of a light microscope?
The shortest wavelength of light used to illuminate the specimen.
When biologists wish to study the internal ultrastructure of cells, they most likely would use
A transmission electronic microscope.
The advantage of light microscopy over electron microscopy is that
light microscopy allows one to view dynamic processes in living cells.
A primary objective of cell fractionation is to
Separate the major organelles so their particular functions can be determined
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 size and weight of the component
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.
nucleus, mitochondria, ribosomes
Quantum dots are small (15-30nm diameter), bright particles visible using light microscopy. If the dots can be specifically bound to individual proteins on a plasma membrane of a cell, which of the following correctly describes the advantage of using quantum dots in examining proteins?
The dots permit the motion of the proteins to be determined more precisely.
The volume enclosed by the plasma membrane of plant cells is often much larger than the corresponding volume in animal cells. The most reasonable explanation for this observation is that
Plant cells contain a large vacuole that reduces the volume of the cytoplasm.
Which of the following comparisons between prokaryotic and eukaryotic cells is incorrect?
The lack of organelles in prokayotes means that the basic cellular functions are different in prokaryotics than in eukaryotes.
Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?
Which of the following compounds require the presence of the nuclear pores to move between the cytoplasm and the interior of the nucleus?
rRNA, ,mRNA, proteins synthesized in the cytoplasm that are part of ribosomes.
Which of the following organelles is not a common destination for small vesivles that bud off the Golgi apparatus?
Which of the following incorrectly matches the type of cell, type of protein, and site of the protein's synthesis?
prokaryote, secreted protein, free cytoplasmic ribosome
Under which of the following conditions would you expect to find a cell with a predominance of free ribosomes.
a cell that is producing cytoplasmic enzymes.
Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?
smooth endoplasmic reticulum
Which structure is the site of the synthesis of proteins that may be exported from the cell?
Which of the following structures is most directly associated with the secretion of compounds that will become part of the plant cell wall?
The Golgi apparatus has a polarity or sideness to its structure and function. Which of the following statements correctly describes this polarity?
All of the above correctly describe polar characteristics of the Golgi function
Which of the following is probably the most common route for membrane flow in the endomenbrane system?
rough ER-vesticles-Golgi-plasma membrane
The fact that the outer membrane of the nuclear envelope has bound ribosomes allows one to most reliably conclude that
at least some of the proteins that funtion in the nuclear envelope are made by the ribosomes on the nuclear envelope.
The difference in lipids and proteins composition between the membranes of the endomembrane system is largely determined by
the function of the Golgi apparatus in sorting membrane components
In animal cells, hydrolytic enzymes are packaged to prevent general destruction of cellular components. Which of the following organelles functions in this compartmentalization?
Which of the following statements correctly describes somes aspect of protein excretion in prokaryotic cells?
Proteins that are excreted by prokaryotes are synthesized on ribosomes that are bound to the cytoplasmic surface of the plasma membrane.
contains enzymes that transfer hydrogen from various substrates to oxygen, producing H2O2
Of the following, what do both mitochondria and chloroplasts have in common?
A, B, and C are correct
Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?
Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell though
Which of the following statements about the cytoskeleton is incorrect?
Microfilaments are structurally rigid and resist compression, while microtubules resist tension (stretching).
All of the following structures and proteins are directly associated with movement in cells by cells except
All of the following serve an important role in determining or maintaining the structure of plant cells. Which of the following are distinct from the others in terms of composition?
Plant cell walls
Which of the following relationships between cell structures and their respective functions is not correct?
Chloroplasts: chief sites of cellular respiration?
All of the following are correct matches for the location of a protein and the location of its synthesis except
mitochondrial matrix protein-rough ER
A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from
a plant or an animal
Which of the following is not a known function of the cytoskeleton?
to maintain a critical limit on cell size