Ch. 2

An organism of the genus Staphylococcus is ________, while an organism of the genus Spirochaeta is ________. A) spherical / rod shaped B) rod shaped / coiled C) spherical / coiled D) coiled / spherical

Bacteria with type IV pili A) possess tubular or stalk-like extensions of their cells. B) likely exhibit twitching motility. C) have capsules that promote dehydration. D) live in aquatic environments.

The terms "run" and "tumble" are generally associated with A) eukaryotic cells. B) nutrient transport. C) chemotaxis. D) clustering of certain rod-shaped bacteria.

The morphology of a cell influences its A) motility. B) metabolism. C) surface-to-volume ratio. D) motility and surface-to-volume ratio.

Compared to Eukaryotes, Bacteria and Archaea have ________ surface-to-volume ratios, causing ________ nutrient exchange. A) lower / lower B) lower / higher C) higher / lower D) higher / higher

The cytoplasmic membrane could best be described as A) an impermeable barrier. B) a passive conduit for intracellular transport. C) a highly selective permeability barrier. D) a rigid structure that protects the cell.

The use of the Gram stain in microbiology is important because it differentiates A) Bacteria from Archaea. B) prokaryotic from eukaryotic cells. C) bacterial cells with different types of cell walls. D) archaeal cells with different types of metabolism

Some archaea have unique phospholipids in their cytoplasmic membrane that A) form a monolayer due to the presence of diglycerol tetraethers. B) form a bilayer due to the presence of sterols. C) form a stable ring structure due to the presence of crenarchaeol. D) form a bilayer due to the presence of phosphatidylethanolamine.

Transport proteins located in the cytoplasmic membrane are necessary when A) diffusion will not allow adequate amounts of a substance to enter the cell. B) movement into the cell is against a concentration gradient. C) the level of nutrients in nature is very low. D) nutrient concentration is very low in the environment, is higher inside of the cell, or diffusion is not possible.

Cells move polar molecules across the cell membrane against a concentration gradient using A) energy and transport proteins. B) simple diffusion. C) modifications to membrane lipids. D) random molecular movement.

You have discovered a new microorganism and would like to classify it as a eukaryote or a prokaryote. To investigate this question you prepare a slide with a simple stain and view it with a light microscope with a 40X objective lens and 10X ocular lens. You also prepare a control slide using Saccharomyces cerevisiae (a unicellular eukaryote). You can see the cells on your control slide, but you don't see cells when you look at your unknown microorganism. What can you conclude from this experiment? A) The experiment failed to visualize the organism because the stain killed it. B) Your new unknown microorganism is probably a virus. C) The cells of the new unknown microorganism may be too small to see with the objective and ocular lenses you used. D) The new unknown microorganism is probably an archaeon.

Bacteria stain as gram-positive or gram-negative because of differences in the cell A) wall. B) cytoplasm. C) nucleus. D) chromosome.

You are given an electron micrograph of a bacterial cell. In the micrograph you can clearly see three thin layers of different densities surrounding the cell. Based on the micrograph, you can infer that this cell is ________ and would appear ________ after application of the Gram stain procedure. A) gram-positive / purple B) gram-negative / pink C) gram-positive / pink D) gram-negative / purple

The cell wall of a Gram-positive bacterium is composed of a thick ________ layer. A) protein B) poly-β-hydroxybutryic acid (PHB) C) lipopolysaccharides (LPS) D) peptidoglycan

You have discovered a new coccoid-shaped microorganism with no nucleus, a rigid cell wall, and a diameter of 2 μm. Chemical tests reveal that its cell wall does NOT contain peptidoglycan. The new microorganism is A) most likely a bacterium. B) most likely a eukaryote. C) most likely an archaeon. D) either a bacterium or an archaeon.

The lipopolysaccharide (LPS) layer is found ONLY in the cell walls of A) gram-positive Bacteria. B) gram-negative Bacteria. C) Archaea. D) Eukarya.

An endotoxin is A) the toxic portion of the LPS. B) a toxin produced within archaeal cells. C) a toxin known for its primary attack on the epidermis of mammals. D) a toxin produced in the periplasm of most bacteria.

Hydrolytic enzymes function in the A) initial degradation of nutrients. B) transport of substrates within the cell. C) chemotactic response, particularly in gram-negative Bacteria. D) regeneration of the periplasm.

Using phase contrast microscopy on a wet mount of live cells, you observe motile bacilli moving rapidly and randomly through the field of view, changing directions after a brief tumble and taking off in a different direction. These cells are exhibiting ________ motility. A) twitching B) swimming C) gliding D) twitching or gliding

Which of the following statements is FALSE? A) A flagellar protein subunit is flagellin. B) In flagellar motion, the basal body acts as a motor. C) Flagellar rotation generates ATP. D) The hook is the wider region at the base of the flagellum

Which of the following statements is TRUE? A) Fimbriae are generally longer and less numerous than flagella. B) Fimbriae are involved in genetic exchange between cells. C) Hami are common in Bacteria but not found in Archaea. D) Fimbriae are usually shorter than flagella whereas pili are involved in genetic exchange.

Cellular inclusions in prokaryotic cells serve to A) store energy rich compounds. B) protect DNA. C) position cells in the appropriate environment for survival. D) store energy rich compounds and position cells in the appropriate environment for survival.

A major function of prokaryotic gas vesicles is to A) confer buoyancy on cells by decreasing their density. B) serve as a reservoir for oxygen and carbon dioxide. C) keep the cell's organelles separated during flagellar motion. D) store oxygen for aerobic growth when oxygen becomes depleted in the environment.

The membrane of a gas vesicle is composed of A) various phospholipids. B) proteins. C) carbohydrates. D) both glycoproteins and phospholipids.

What is the biological function of endospores? A) They are bacterial reproductive structures. B) They enable organisms to endure extremes of temperature, drying, and nutrient depletion. C) They transport toxins. D) Endospores can serve as reproductive structures, enable survival in harsh environments, and transport toxins.

The lipids in the cytoplasmic membrane of Bacteria and ________ contain ester linkages, while the cytoplasmic membrane of ________ contain ether linkages. A) Archaea / Eukarya B) Archaea / fungi C) Eukarya / prokaryotes D) Eukarya / Archaea

Based on your knowledge of porins from the chapter, what is the best description of the specific type of porin called an aquaporin? A) water transport proteins B) molecules that prevent water from crossing a membrane C) enzymes involved in the generation of water within cells D) cations bound to water molecules

________ are charged molecules that are partially responsible for the ________ charge of the gram-positive bacterial cell surface. A) Diaminopimelic acids / positive B) Teichoic acids / negative C) Phospholipids / negative D) Peptide interbridges / neutral

Although the inner leaflet of the gram-negative outer membrane is composed mainly of phospholipids, the outer leaflet of the outer membrane contains A) pseudopeptidoglycans. B) lipoteichoic acids. C) poly-β-hydroxybutyric acids (PHB). D) lipopolysaccharides (LPS).

One of the many types of proteins found in the cytoplasmic membrane is involved in the chemotactic response and is called a A) hydrolytic enzyme. B) chemoreceptor. C) binding protein. D) porin.

When does endospore formation commence? A) when bacterial growth ceases due to limitation of an essential nutrient B) when the bacterium is undergoing binary fission C) when bacteria are dividing exponentially D) following bacterial death

Which is/are a function(s) of the cytoplasmic membrane in prokaryotes? A) It functions as a permeability barrier. B) It is an anchor for many proteins involved in bioenergetic reactions and transport. C) It is a major site of energy conservation. D) It serves as a permeability barrier, a docking station for proteins involved in bioenergetics reactions and transport, and a site for energy conservation.

All eukaryotes contain A) a membrane-enclosed nucleus. B) mitochondria. C) hydrogenosomes. D) a nucleus, mitochondria, and hydrogenosomes.

Mitochondria and hydrogenosomes are similar in that they both A) are the site of energy production in eukaryotic cells. B) evolved via endosymbiosis of bacterial cells. C) are the site of aerobic respiration. D) evolved via endosymbiosis and are sites for aerobic respiration and energy production.

Membrane-enclosed organelles, such as nuclei, lysosomes, endoplasmic reticulum, mitochondria, and chloroplasts A) form specialized compartments within eukaryotic cells for specific functions to occur. B) increase the structural complexity of eukaryotic cells. C) help large eukaryotic cells overcome the limitations of diffusion imposed by their large cell size. D) increase structural complexity, help eukaryotes overcome diffusion limitation due to their size, and form specialized environments for specific functions to occur.

The Golgi complex functions to A) modify and secrete proteins to the external environment. B) sort proteins used within the cell. C) both modify and sort proteins into those destined for secretion and those that function in membrane structures. D) synthesize proteins.

The membrane-enclosed compartments that contain digestive enzymes in eukaryotic cells are called A) cristae. B) mitosomes. C) lysosomes. D) stromas.

Where within a eukaryotic cell is ribosomal RNA (rRNA) synthesized? A) cytoplasm B) lysosome C) mitochondrion D) nucleolus

The energy source derived from the charge separation across the cytoplasmic membrane is referred to as A) the proton motive force. B) carbohydrate charging. C) adenosine triphosphate. D) the voltage source.

Based on the table of attributes given below, which of the following statements are FALSE about the two organisms? A) Bacterium A is more resistant to heat and ultraviolet light. B) Bacterium B likely forms a slime layer better than Bacterium A. C) Bacterium B is likely to exhibit motility. D) Both bacteria may attach to surfaces.

Small acid-soluble proteins (SASPs) protect DNA from ultraviolet light and are found in high numbers within A) gram-positive Bacteria. B) endospores. C) inclusion bodies. D) gram-negative Bacteria.

The peptide interbridge crosslinking between peptidoglycan layers is found ONLY in the cell walls of A) Archaea. B) Eukarya. C) gram-positive Bacteria. D) gram-negative Bacteria.

Type IV pili are involved in A) attachment of cells to surfaces. B) twitching motility. C) pathogenesis. D) attachment to surfaces, twitching motility, and pathogenesis.

Eukaryotes have ________ in their cytoplasmic membranes, which serve to strengthen and stabilize the membrane and make it less flexible. Many bacteria have similar molecules, known as ________, in their cytoplasmic membranes that have a similar role. A) ether bonds / ester bonds B) lipids / phospholipids C) sterols / hopanoids D) phospholipids / lipopolysaccharides

The rigid layer that is present in the cell walls of Bacteria that is primarily responsible for the strength of the wall is known as A) pseudomurein. B) S-layer. C) cellulose. D) peptidoglycan.

Some of the intestinal symptoms elicited by pathogens such as Salmonella, Shigella, and Escherichia are due to the presence of A) pseudomurein. B) S-layers. C) lipopolysaccharides. D) peptidoglycan.

Using bright-field microscopy to look at a slide prepared with a basic dye you observe cells with a clear inner compartment within the cell at 400X magnification. The cell is most likely a(n) A) prokaryote. B) bacterium. C) archaeon. D) eukaryote.

While examining cellular material, you find that organelle DNA is present. What organelle(s) must be within the sample? A) lysosomes B) rough or smooth endoplasmic reticulum C) chloroplasts or mitochondria D) Golgi complex

Which of the following is evidence for the endosymbiotic theory? A) Mitochondria have circular DNA. B) The nucleus is surrounded by a nuclear membrane. C) Chloroplasts have thylakoids. D) The rough endoplasmic reticulum has ribosomes.

Actin is found within ________. A) the prokaryotic cytoskeleton. B) eukaryotic microfilaments. C) eukaryotic microtubules. D) eukaryotic intermediate filaments.

Which of the following statements is TRUE? A) Eukaryotic flagella rotate in the same manner as prokaryotic flagella. B) Lysosomes synthesize proteins and carbohydrates. C) Cilia generally move with a slow, whiplike motion. D) The major function of the rough endoplasmic reticulum is lipid synthesis.

Archaeans have archaella that rotate like bacterial flagella though they A) have greater diameters than bacterial flagella. B) are longer than bacterial flagella. C) only rotate in one direction. D) consist of multiple protein types.

You find endospores of a particular species. Which of the following is most likely TRUE of this species? A) It is an archaean. B) It is a gram positive bacterium. C) It is a gram negative bacterium. D) It is equally likely to be an archaean, a gram positive bacterium, or a gram negative bacterium.

(T/F) In general, most cell inclusions function as energy reserves or as a reservoir of structural building blocks.

(T/F) Smaller prokaryotic cells generally grow faster than larger ones due to a higher surface-area to-volume ratio.

(T/F) In general, lipids in archaeal cytoplasmic membranes lack true fatty acids.

(T/F) Some membrane proteins are involved in bioenergetic reactions, while others are involved in membrane transport.

(T/F) Both hydrophilic and charged molecules readily diffuse through the cytoplasmic membrane.

(T/F) Teichoic acids are commonly found in gram-negative cell walls

(T/F) Despite the invariance of the backbone of peptidoglycan, there are more than 100 different types of peptidoglycan.

(T/F) Lysozyme is an enzyme that can ultimately lyse and kill eukaryotic cells by breaking β-1, 4- glycosidic bonds in peptidoglycan.

(T/F) Porins are channels in the outer membranes of gram-positive Bacteria.

(T/F) A bacterial cell is interpreted as gram-positive when it forms purple insoluble crystal violetiodine complexes within the cell during the Gram stain.

(T/F) In general, swimming is performed with flagella, whereas gliding uses other cellular components such as pili.

(T/F) Chemotaxis is a sensory response affecting the rotational direction of the flagellar motor.

(T/F) Photoreceptors are analogous to chemoreceptors in that they are both proteinaceous sensors.

(T/F) Pathogenic bacteria that contain S-layers are protected against host defense mechanisms

(T/F) Poly-β-hydroxybutyric acid (PHB) is a carbon- and energy-storing polymer.

(T/F) Mitochondria and chloroplasts have their own DNA and ribosomes, which supports the endosymbiotic hypothesis.

(T/F) Macromolecules resulting from lysosomal digestion are used in cellular biosynthesis and energy generation.

(T/F) Viewing the shape of a bacterial or archaeal cell using a microscope gives a great deal of information about the metabolism and lifestyle of the organism.