Chapter 3 Flashcards
A research laboratory is investigating environmental factors that would inhibit the growth ofArchaea. One question they have is if adding the antibiotic penicillin would be effective in controlling their growth. What do you think the outcome would be if they tried this?
A. The penicillin will enhance the growth of theArchaeaby providing a rich nutrient source. B. The penicillin will inhibit cell wall formation in theArchaea, killing them. C. The penicillin wouldn't affect theArchaeabecause it prevents crosslinking of peptidoglycan-Archaeadon't have this compound in their cell walls. D. The penicillin will slow down the growth of theArchaeaby damaging the cell wall, but they will still be able to grow somewhat.
C. The penicillin wouldn’t affect theArchaeabecause it prevents crosslinking of peptidoglycan-Archaeadon’t have this compound in their cell walls.
Which microscope would be the BEST selection for examination of a virus?
A. Confocal scanning laser microscope B. Scanning electron microscope C. Atomic force microscope D. Dark-field light microscope
B. Scanning electron microscope
Prokaryotes may ingest particles via phagocytosis.
True
False
False
Cilia and flagella project from the cell and are not covered by cytoplasmic membrane.
True
False
False
The microscope that allows the specimen to appear three-dimensional is the:
A. dark-field microscope. B. fluorescence microscope. C. phase contrast microscope. D. interference microscope.
D. interference microscope.
Extrachromasomal DNA is found in ____________________________.
A. mitochondria AND plasmids B. mitochondria C. nucleoid D. nucleoli E. plasmids
A. mitochondria AND plasmids
Which is not true of the cytoplasmic membrane?
A. It defines the boundaries of the cell. B. It is a semipermeable barrier. C. It consists mainly of a fixed, static, phospholipid bilayer. D. It uses proteins as selective gates and sensors. E. All of the choices are true.
C. It consists mainly of a fixed, static, phospholipid bilayer.
BacillusandClostridiumare medically relevant groups of bacteria that characteristically stain acid-fast.
True
False
False
A research lab is trying to produce new antibiotics. They come up with drugs that detach the hydrophilic heads from the phospholipids in plasma membranes. This drug:
A. would generally not be toxic enough to damage Gram-negative bacteria, as their plasma membranes lie under a thick layer of peptidoglycan. B. would be highly toxic and completely useless for human beings-we also have plasma membranes with hydrophilic head groups! C. would be highly toxic only to bacteria, making it an excellent drug to develop and test further. Humans have a different phospholipid structure in their cell plasma membranes than bacteria. D. would be highly toxic for human beings, but might be useful as a topical antibiotic skin cream. The top layer of skin cells is dead anyway, so it wouldn't matter if this damaged those cells. It could NOT be taken internally, though, by human beings.
D. would be highly toxic for human beings, but might be useful as a topical antibiotic skin cream. The top layer of skin cells is dead anyway, so it wouldn’t matter if this damaged those cells. It could NOT be taken internally, though, by human beings.
Phagocytosis
A. is the secretion of proteins. B. is the formation of a lysosome. C. is the ingestion of particles and may be performed by animal cells. D. is the ingestion of particles and may be performed by bacteria AND is the formation of a lysosome. E. is the ingestion of particles and may be performed by bacteria.
D. is the ingestion of particles and may be performed by bacteria AND is the formation of a lysosome.
The structures used for motility in both eukaryotes and prokaryotes are:
A. pili. B. cilia. C. flagella. D. fimbriae.
C. flagella.
The macromolecule found in the cell walls of all bacteria is A. lipid A. B. teichoic acid. C. peptidoglycan. D. glycocalyx.
C. peptidoglycan.
Immunofluorescence:
A. utilizes acridine orange. B. uses fluorescently tagged molecules, makes use of the specificity in binding of antibodies, AND would require a special UV microscope. C. makes use of the specificity in binding of antibodies. D. uses fluorescently tagged molecules. E. would require a special UV microscope.
B. uses fluorescently tagged molecules, makes use of the specificity in binding of antibodies, AND would require a special UV microscope.
Which of the following stains is/are considered differential? A. Flagella stain. B. Acid-fast stain AND Gram stain. C. Acid-fast stain. D. Capsule stain. E. Gram stain.
B. Acid-fast stain AND Gram stain.
In viewing a microscopic specimen, oil is used to
A. increase the refraction. B. increase the reflection. C. increase the resolution. D. decrease the refraction. E. decrease the refraction AND increase the resolution.
E. decrease the refraction AND increase the resolution.
Individual atoms on the surface of prepared samples can be observed by using the:
A. dark-field microscope. B. atomic force microscope. C. phase contrast microscope. D. scanning electron microscope.
B. atomic force microscope.
The cell wall of Gram-positive bacteria::
A. contains an outer membrane containing LPS. B. contains a thin layer of peptidoglycan. C. contains a thin layer of peptidoglycan AND contains an outer membrane containing LPS. D. contains a thick layer of peptidoglycan. E. is, due to its thickness, an excellent barrier to most molecules.
D. contains a thick layer of peptidoglycan.
Penicillin would be most effective against
A. non-growing bacteria. B. Gram-negative bacteria. C. Gram-positive bacteria. D. growing bacteria. E. growing bacteria AND Gram-positive bacteria.
E. growing bacteria AND Gram-positive bacteria.
Specimens can be observed at the atomic level using a(n)
A. scanning electron microscope. B. transmission electron microscope. C. atomic force microscope. D. All of the choices are correct. E. None of the choices is correct.
C. atomic force microscope.
Which is not true of mitochondria and chloroplasts?
A. They contain DNA and 70S ribosomes. B. They generate ATP. C. They are capable of performing protein synthesis. D. They are found in all organisms.
D. They are found in all organisms.
Endospores are
A. a dormant cell type. B. sensitive to damaging environmental conditions. C. a form of reproduction. D. an obligate intracellular parasite.
A. a dormant cell type.
Mitochondria and chloroplasts are thought to have once been free-living bacteria that invaded another cell.
True
False
True
If everything else is equal, the best way to observe more details in a microscopic specimen is to
A. increase resolution. B. increase magnification.
A. increase resolution.
A newly developed antibiotic drug shows promise by inhibiting prokaryotic 70S ribosomes in initial studies. However, when animal studies are begun, it’s noted that it also inhibits growth of animal cells. Aren’t prokaryotic ribosomes different from eukaryotic ribosomes? How can this be happening?
A. While the proteins made in the cytosol of eukaryotic cells are, indeed, produced from the 80S eukaryotic ribosome, mitochondria and chloroplasts possess 70S ribosomes. This drug might be impairing the activity of mitochondria in animal cells. B. While the proteins made in the cytosol of eukaryotic cells are, indeed, produced from the 80S eukaryotic ribosome, mitochondria and chloroplasts possess 70S ribosomes. This drug might be impairing the activity of chloroplasts in animal cells. C. Perhaps the ribosomes aren't as different as we thought, so a drug can affect and impair both of them. D. Perhaps the scientists accidently combined their cultures of animal and bacterial cells-this might indicate an impairment in growth in the culture. In reality, it's still just impairing the bacterial cells.
A. While the proteins made in the cytosol of eukaryotic cells are, indeed, produced from the 80S eukaryotic ribosome, mitochondria and chloroplasts possess 70S ribosomes. This drug might be impairing the activity of mitochondria in animal cells.
