The advantage of light microscopy over electron microscopy is that
Light microscopy allows one to view dynamic processes in living cells.
A primaryobjective of cell fractionation is to
Separate the major organelles so that their particular functions can be determined.
What is 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.
All of the following are part of a prokaryotic cell except: A. DNA, B. a cell wall, C. a plasma membrane, D. ribosomes, E. an endoplasmic reticulum.
E. an endoplasmic reticulum.
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 is that
Plant cells contain a large vacuole that reduces the volume of the cytoplasm.
What is a major cause of the size limits for certain types of cells?
The need for a surface area of sufficient area to allow the cell's functions.
Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules: A. Lipids, B. Starches, C. Proteins, D. Steroids, E. Glucose.
Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?
Smooth endoplasmic reticulum.
What structure is the site of the synthesis of proteins that may be exported from the cell?
The Golgi apparatus has a polarity or sideness to its structure and function. Which of the following statements correctly describes this polarity? A. Transport vesicles fuse with 1 side of the Golgi and leave from the opposite side. B. Proteins in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other. C. Lipids in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other. D. Soluble proteins in the cisternae (interior) or the Golgi may be sorted and modified as they move from one side of the Golgi to the other. E. All of the above correctly describe polar characteristics of the Golgi function.
E. All of the above correctly describe polar characteristics of the Golgi function.
In animal cells, hydrolytic enzymes are packaged to prevent general destruction of cellular components. What organelle functions in this compartmentalization?
What statement describes some aspect of protein disposal from porkaryotic cells?
Proteins that are excreted by prokkaryotes are synthesized on ribosomes that are bound to the cysoplasmic surface of the plasma membrane.
Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large and complex lipids. What cellular organelle must be involved in this condition?
The liver is involved in detoxification of many poisons and drugs. What structure is primarily involved in this process and therefore abundant in liver cells?
Which of the following produces and modifies polysaccharides that will be secreted? A. Lysosome, B. Vacuole, C. Mitochondrian, D. Golgi Apparatus, E. Peroxisome.
D. Golgi Apparatus.
Which of the following contains hydrolytic enzymes? A. Lysosome, B. Vacuole, C. Mitochondrion, D. Golgi Aparatus, E. Peroxisomes.
Which of the following is a compartment that often takes up much of the volume of a plant cell? A. Lysosome, B. Vacuole, C. Mitochondrion, D. Golgi Aparatus, E. Peroxisomes.
Which is one of the main energy transformers of cells? A. Lysosome, B. Vacuole, C. Mitochondrion, D. Golgi Aparatus, E. Peroxisomes.
Which of the following contains its own DNA and ribosomes? A. Lysosome, B. Vacuole, C. Mitochondrion, D. Golgi Aparatus, E. Peroxisomes.
What contains enzymes that transfer hydrogen from various substrates to oxygen?
Grana, thylakoids, and stroma are all components found in
Organelles other than the nucleus that contain DNA include: A. Ribosomes, B. Mitochondria, C. Chloroplasts, D. B. and C. only, E. A., B., and C.
D. B. and C. only.
The chemical reactions involved in respiration are virtually identical between prokaryotic and eukaryotic cells. In eukaryotic cells, ATP is synthesized primarily on the inner membrane of the mitochondria. Where are the corresponding reactions likely to occur in prokaryotic pespiration?
On the inner plasma membrane.
A biologist ground up some plant leaf cells and then centirfuged the mixture to fractionate the organelles. Organelles in one of the heavier fractions could produce ATP i nthe light, while organelles in the lighter fraction could produce ATP in the dark. The heavier and lighter fractions are most likely to contain, respectively,
Chloroplasts and mitochondria.
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 danimal.
The mitochondrion, like the nucleus, has two or more membrane layers. How is the innermost of these layers different from that of the nucleus?
The inner mitochondrial membrane is highly folded.
Why isn't the mitochondrion classified as part of the endomembrane system?
Its structure isn't derived from the ER.
The peroxisome gets its name from its interaction with hydrogen peroxide. If a liver cell is detoxifying alcohol and some other poisons, it does so by removal of hydrogen from the molecules. What, then, do the enzymes of the peroxisome do?
Transfer the hydrogens to oxygen molecules.
How does the cell multiply its peroxisomes?
The split in two after they are too large.
Motor proteins provide for molecular motion in cells by interactin with what types of cellular structures?
Cells can be described as habing a cytoskeleton of internal structures that contribute to the shape, organization, and movement of the cell. Which of the following are part of the cytoskeleton? A. The nuclear envelope, B. Mitochondria, C. Microfilaments, D. Lysosomes, E. Nucleoli.
Of the following, which cell structure would most likely be visible with a light microscope that has been manufactured to the maximum resolving power possible? A. Mitochondrion, B. Microtubule, C. Ribosome, D. Largest microfilament, E. Nuclear pore.
The differences among the three categories of cytoskeletal elements would suggest that each of the following has specialized roles. Which of the following is a correct match? A. Microfilaments and the nuclear lamina, B. Microtubules and cleacage furrow formation, C. Microfilaments and ciliary motion, D. Intermediate filaments and cytoplasmic streaming, E. Microtubles and chromosome movement.
E. Microtubles and chromosome movement.
Centrioles, cilia, flagella, and basal bodies have remarkably similar structural elements and arrangements. This leads us to which of the following as a probable hypothesis.
Natural selection for motility must select for microtubular arrays incircular patterns.
If an individual has abnormal microtubules, due to a hereditary condition, in which organs or tissues would you expect dysfunction?
Sperm, laryinx, and trachea.
Microfilaments are well known for their role in which of the following? A. Ameboid movement, B. Formation of cleavage furrows, C. Contracting of muscle cells, D. A. and B. only, E. A., B., and C.
E. A., B., and C.
All of the following serve an important role in determining or maintaining the structure of plant cells. Which of the following are distince from the others in their composition? A. Microtubles, B. Microfilaments, C. Plant cell walls, D. Intermediate filaments, E. Nuclear lamina.
C. Plant cell walls.
Which of the following relationships between cell structures and their respective functions is correct? A. Cell wall: support, protection, B. Chloroplasts: chief sites of cellular respiration, C. Chromosomes: cytoskeleton of the nucleus, D. Ribosomes: secretion, E. Lysosomes: formation of ATP.
A. cell wall: support, protection.
A cell lacking the ability to make and secrete glycoproteins would most likely be deficient in its: A. Nuclear DNA, B. Extracellular matrix, C. Golgi apparatus, D. B. and C. only, E. A., B., and C.
D. B. and C. only.
The extracellurar matrix is thuoght to participate in the regulation of animal cell behavior by communicating information from the outside to the inside of the cell via what?
Plasmodesmata in plant cells are most similar in function to what structures in animal cells?
Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through
What makes it necessary for animal cells, although they have no cell walls, to have intercellular junctions?
Large molecules, especially proteins, do not readily get through one, much less two adjacent cell membranes.
What statement correctly characterizes bound ribosomes?
Bound ribosomes generally synthesize membrane proteins and secretory proteins.
Which structure is not part of the endomembrane system? A. nuclear membrane, B. Chloroplast, C. Golgi apparatus, D. Plasma membrane, E. ER.
Cells of the pancreas will incorporate radioactivity labeled amino acids into proteins. This "tagging" of newly synthesized proteins enables a researcher to track their location. In this case, we are tracking an enzyme secreted by pancreatic cells. What is its most likely pathway?
ER -> Golgi -> Vesicles that fuse with plasma membrane.
What structure is common to plant and animal cells?
What is a true statement about the cytoskeleton?
Movement of cilia and flagella is the result of motor proteins causing microtubules to move relative to each other.
Recent evidence shows that the extracellular matrix can take part in regulating the expression of genes. A likely possibility for this might be what?
Mechanical signals of the ECM can alter the cytoskeleton, which can alter intracellular signalin.