Microbiology Test 2 (Chapter 4: Prokaryotes and Eukaryotes)
The DNA found in most bacterial cells
is circular in structure.
Functions of the glycocalyx include all of the following EXCEPT
binary fission
In the figure, which diagram of a cell wall contains teichoic acids?
A
Which drawing in the figure possesses an axial filament?
A
Label the two parts
A - Gram Positive B- Gram Negative
Why is ATP necessary for active transport?
ATP provides energy to transfer material against its concentration gradient.
Which type of active transport protein uses one protein to pump two different molecules?
Antiport and Symport
In the figure, which diagram of a cell wall contains porins?
B
In the figure, which diagram of a cell wall is a gram-negative cell wall?
B
In the figure, which diagram of a cell wall is decolorized by a brief exposure to alcohol?
B
In the figure, which diagram of a cell wall is resistant to many antibiotics (e.g., penicillin)?
B
In the figure, which diagram of a cell wall possesses lipid A/endotoxin responsible for symptoms associated with infection?
B
Which drawing in the figure is streptococci?
D
How is the genetic information of bacterial cells organized differently from that of eukaryotic cells?
Bacterial DNA floats free within the cytoplasm and is not enclosed within a nuclear envelope, whereas eukaryotic DNA is enclosed in a membrane-bound structure known as the nucleus.
In the figure, which diagram of a cell wall has a structure that protects against osmotic lysis?
Both A & B
Which molecule shown in the animation, the square or the circle, is moving against its concentration gradient?
Both the circle and the square
Which of the following statements is TRUE?
Endospores allow a cell to survive environmental changes by producing a dormant period with no growth.
Endospores are a reproductive structure.
False
Which statement regarding the structure or function of ribosomes is correct?
In eukaryotes, the ribosomes found in chloroplasts and mitochondria are 70S ribosomes, which are similar in size to prokaryotic ribosomes.
Which of the following statements accurately describes bacterial cell walls?
In gram-negative bacteria, the thin layer of peptidoglycan is surrounded by an outer membrane made of phospholipids, lipopolysaccharides, and proteins.
Which organelle would play the most direct role in eliminating bacteria engulfed by a phagocytic white blood cell?
Lysosome
How will the prescribed penicillin kill S. pyogenes that is causing Shelly's infection?
Penicillin will interfere with peptidoglycan synthesis, ultimately weakening the cell wall and leading to cellular lysis.
Which of the following facts does NOT provide evidence for the endosymbiotic theory?
Prokaryotes contain peptidoglycan in their cell walls.
In bacterial ribosomes, a small 30S subunit and a large 50S subunit come together to produce the functional 70S ribosome. Why isn't it an 80S ribosome?
S stands for Svedberg units, which indicates the relative rate of sedimentation due to size, weight, and shape of a particle. The numbers aren't strictly additive.
How is simple diffusion different from other types of passive transport?
Simple diffusion does not require a permease.
How do spirochetes and spirilla differ?
Spirilla have external flagella but spirochetes have axial filaments.
Drag the labels onto the flowchart to trace the movement of proteins through the endomembrane system and out of the cell.
Start: Rough ER (Manufacturing) Vesicle from ER (Transport) Golgi Apparatus (Processing) Vesicle from Golgi (Transport) Plasma Membrane (Secretion) FINISH
What will happen to a cell that is placed in a solution containing a high concentration of sugar, a molecule that cannot pass across the cell membrane?
The cell will lose its interior water, causing it to shrivel up and possibly die.
What effect will the penicillin have on Shelly's cells?
The penicillin will not have any impact on Shelly's cells because it targets peptidoglycan, which is found only in bacteria.
Which of the following statements about gram-negative cell walls is FALSE?
They are sensitive to penicillin.
If you observe rod-shaped red cells after the Gram stain, you can assume their cell walls contain endotoxin.
True
Spheroplasts, protoplasts, and mycoplasms are bacterial cells without cell walls.
True
The cell walls of bacteria are responsible for the shape of the bacteria and the difference in the Gram stain reaction.
True
Which transport protein employs transporters that move molecules only in one direction?
Uniport and Symport
How is osmosis different from simple diffusion?
Water movement is driven by the concentration of solutes rather than its own concentration.
Which type of solution would cause a bacterium with a weak or damaged cell wall to burst as water moves into the cell?
a hypotonic solution
By which of the following mechanisms can a cell transport a substance from a lower to a higher concentration?
active transport
Cells may frequently find themselves in an environment with very low extracellular concentrations of substances needed in higher amounts inside the cell. To obtain these needed items, such cells would be most likely to engage in
active transport
Nonspecific permeases
allow a variety of molecules to cross the cytoplasmic membrane.
Which structure protects bacteria from being phagocytized?
capsule
Which of the following is NOT found or observed to occur in both mitochondria and prokaryotes?
cell wall
Which of the following pairs is mismatched?
centrosome - food storage
In bacteria, photosynthetic pigments are found in
chromatophores
Which of the following is NOT a typical characteristic of most bacterial plasma membranes?
contains cholesterol
Which of the following is NOT characteristic of the glycocalyx found in bacteria?
creates a slimy, slippery coating that prevents bacteria from attaching to surfaces
The structural framework in a cell is the
cytoskeleton
A particular type of inclusion body that is used to orient bacteria in three-dimensional space in a fluid environment is the
gas vacuole
Which of the following is part of the endomembrane system?
golgi apparatus
You are observing a Gram stain of spherical-shaped microorganisms that are linked in a chain and stain purple. How would you describe these bacteria using the correct terminology for the cell shape and arrangement?
gram-positive streptococci
You have isolated a motile, gram-positive cell with no visible nucleus. You can safely assume that the cell
has a cell wall
Each of the following statements concerning the gram-positive cell wall is true EXCEPT
it protects the cell in a hypertonic environment.
Which of the following terms best describes the cell in the figure?
lophotrichous flagella
Which of the following organelles breaks down worn-out organelles?
lysosomes
Bacteria are a commonly used organism for studies of genetic material in the research laboratory. The nucleic acids must first be isolated from the cells for these studies. Which of the following would most likely be used to remove the cell wall from gram-positive bacterial cells prior to their lysis for nucleic acid isolation?
lysozyme
What carries instructions for making proteins from the nucleus into the cytoplasm?
mRNA
Where in a cell is ATP made?
mitochondria
Which of the following organelles most closely resembles a prokaryotic cell?
mitochondrion
Where is the genetic information of the cell stored?
nucleus
Antibiotics that target cell wall synthesis ultimately cause bacterial cell death as a result of
osmotic lysis
Fimbriae and pili differ in that
pili are used for transfer of DNA and motility.
What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell?
plasma membrane
In a hypertonic solution, a bacterial cell will typically
plasmolyze
Analysis of the second swab has confirmed that the causative organism is Streptococcus pyogenes, a gram-positive organism. Imagine that you are the technician looking at the Gram stain from Shelly's culture. What would you expect to see as you look through the microscope?
purple, spherical-shaped organisms arranged in chainlike formations Submit
One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by
ribosomes
Which one of the following pairs is mismatched?
ribosomes - carbon storage
Endospores are highly resistant to harsh environmental conditions due to all EXCEPT which one of the following?
small triggering molecules called germinants
Where are lipids made in the cell?
smooth ER
Which type of active transport protein moves two molecules into the cell at the same time?
symport
The terms "run" and "tumble" are generally associated with
taxic movements of the cell in response to attractants or repellents.
What will happen if a bacterial cell is pretreated with a lysozyme solution, then placed in distilled water?
the cell will undergo osmotic lysis.
Where are phospholipids most likely found in a prokaryotic cell?
the plasma membrane
