Ch.4: Functional Anatomy of Prokaryotic and Eukaryotic Cells

Which of the following is NOT a structure of prokaryotic cells? a)Chloroplast b)Ribosome c)Chromosome d)Capsule e)Flagellum

a)Chloroplast

Which of the following is NOT characteristic of the glycocalyx found in bacteria? a)Creates a slimy, slippery coating that prevents bacteria form attaching to surfaces b)A structure that can be visualized by negative staining c)If firmly attached, contributes to bacterial virulence d)A viscous coating surrounding the cell made of polysaccharide, polypeptide, or both

a)Creates a slimy, slippery coating that prevents bacteria form attaching to surfaces explanation: Slimy and slippery coating that prevents bacteria form attaching to surfaces would NOT be a characteristic of the bacterial glycocalyx. The bacterial glycocalyx is a viscous (sticky), gelatinous polymer that is external to the cell wall and composed of polysaccharide, polypeptide, or both. Its chemical composition varies widely with the species. For the most part, it is made inside the cell and secreted to the cell surface.

Which of the following bacterial structures is necessary for chemotaxis? a)Flagella b)Capsules c)Metachromatic granules d)Plasmids

a)Flagella explanation: Flagella are necessary for chemotaxis. Bacterial cells can alter the speed and direction of rotation of flagella and thus are capable of various patterns of motility, the ability of an organism to move by itself. One advantage of motility is that it enables a bacterium to move toward a favorable environment or away from an adverse one. The movement of a bacterium toward or away from a particular stimulus is called taxis, for example chemicals (chemotaxis).

Penicillin specifically interferes with peptidoglycan synthesis. Which of the following cells is most likely to be damaged by penicillin? a)Gram-positive bacterial cells b)Human cells c)Yeast cells d)Cells of archaea

a)Gram-positive bacterial cells

Which of the following is NOT true of the gram-negative outer membrane? a)It contains enzymes for energy synthesis. b)It contains lipopolysaccharide. c)It contains lipids also known as endotoxins. d)It has polysaccharide antigens that are useful in bacterial identification. e)It is a part of the gram-negative cell wall.

a)It contains enzymes for energy synthesis.

What will occur if a bacterial cell with a weakened or damaged cell wall is placed in pure water? a)The cell will swell and burst. b)The cell will form a new cell wall. c)The cell will shrink. d)The cell will form endospores. e)The cell will remain the same size.

a)The cell will swell and burst.

Many pathogenic (disease-producing) bacteria produce a(n) __________ that protects them from phagocytosis by host cells. a)capsule b)endospore c)flagellum d)pilus

a)capsule

Spirochetes and spirilla are both spiral-shaped bacteria. However, they differ in that spirochetes have __________ and spirilla do not. a)endoflagella b)fimbriae c)N-acetylglucosamine d)peritrichous flagella

a)endoflagella explanations: The major difference between spirochetes and spirilla is the presence of endoflagella. Spirochetes move by means of axial filaments, or endoflagella, bundles of fibrils that arise at the ends of the cell beneath an outer sheath and spiral around the cell.

All of the following are found in the cell walls of gram-positive bacteria EXCEPT __________. a)lipid A b)lipoteichoic acid c)peptidoglycan d)N-acetylglucosamine e)teichoic acid

a)lipid A

The motility of bacteria with flagella occurs through a series of "runs" and __________. a)tumbles b)phototaxis c)turns d)Chemotaxis

a)tumblesFlagella are necessary for chemotaxis. Bacterial cells can alter the speed and direction of rotation of flagella and thus are capable of various patterns of motility, the ability of an organism to move by itself. One advantage of motility is that it enables a bacterium to move toward a favorable environment or away from an adverse one. The movement of a bacterium toward or away from a particular stimulus is called taxis, for example chemicals (chemotaxis).

You are observing a Gram stain of rod-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? a) Gram-negative staphylococci b)Gram-positive streptobacilli c)Gram-positive tetrads d)Gram-positive coccobacilli

b)Gram-positive streptobacilli

Which of the following is a likely outcome, based on the unique cell structure of members of the genus Mycoplasma? a)Mycoplasma species usually stain gram-positive. b)Mycoplasma species have very flexible cells that can pass through bacteriologic filters. c)Mycoplasma species are susceptible to penicillin. d)Mycoplasma species can release endotoxins when they lyse. e)Mycoplasma species are susceptible to disruption by lysozymes

b)Mycoplasma species have very flexible cells that can pass through bacteriologic filters.

A Gram stain of a wound reveals purple, spherical bacteria that divide and remain attached in grapelike clusters. These are referred to as __________. a)gram-negative spirochetes b)gram-positive staphylococci c)gram-positive tetrads d)gram-positive streptococci

b)gram-positive staphylococci explanation: The best description for these cells would be gram-positive streptobacilli. During the Gram staining procedure, the application of alcohol dehydrated the peptidoglycan trapping the crystal violet-iodine complex in the thick cell wall imparting the purple color. The chainlike pattern would be best described with "strepto," the rod-shape of the cell would best be described with "bacilli," thus "streptobacilli."

The term describing bacteria with flagella distributed over the entire surface of the cell is __________. a)monotrichous b)peritrichous c)lophotrichous d)amphytrichous

b)peritrichous

In a prokaryotic cell, all of the following are functions of either fimbriae or pili EXCEPT __________. a)transfer of DNA b)protection from phagocytosis c)attachment to a surface d)formation of biofilms

b)protection from phagocytosis explanation: Fimbriae and pili do NOT function in protection from phagocytosis. Fimbriae help cells adhere to surfaces and are involved in forming biofilms. Pili are commonly involved in DNA transfer and twitching or gliding motility.

Cocci may be arranged as __________. a)tetrads b)streptococci c)All of the listed answers. d)staphylococci e)diplococcic

c)All of the listed answers.

Which of the following statements about a gram-negative cell wall is FALSE? a)It functions as an endotoxin. b)It maintains the shape of the cell. c)It contains teichoic acid. d)It includes a thin layer of peptidoglycan.

c)It contains teichoic acid.

With a light microscope, which of the following would allow discrimination between eukaryotes and prokaryotes? a)Observation of flagella b)Observation of the plasma membrane c)Observation of nuclei d)Observation of photosynthetic pigment e)Observation of the ribosomes

c)Observation of nuclei

Why is penicillin selectively toxic to bacterial cells but harmless to human cells? a)Penicillin is inactivated within lysosomes of human cells. b)Human cells actively transport penicillin out of the cell. c)Penicillin specifically weakens peptidoglycan, which is found only in bacterial cells. d)Penicillin is rapidly metabolized and destroyed by human cells. e)The glycocalyx of an animal cell provides a barrier through which penicillin cannot pass

c)Penicillin specifically weakens peptidoglycan, which is found only in bacterial cells.

Which of the following pairs is matched correctly? a)Mycoplasma spp.—bacteria that spontaneously, or in response to penicillin or lysozyme, partially lose their cell walls and swell into irregularly shaped bacteria that divide and metabolize and may regain their cell wall b)L form—a wall-less bacterium created by the action of lysozyme; the plasma membrane remains intact, and the cell carries on metabolism c)spheroplast—gram-negative bacteria that are exposed to lysozyme but retain some of the outer membrane d)protoplast—a genus of bacteria that typically do not have cell walls

c)spheroplast—gram-negative bacteria that are exposed to lysozyme but retain some of the outer membrane

The term describing bacteria with flagella that are arranged as a tuft coming from one pole is __________. a) peritrichous b)amphytrichous c)monotrichous d)lophotrichous

d)lophotrichous explanation: The term describing bacteria with flagella that are arranged as a tuft coming from one pole is lophotrichous. Flagella may also be described as peritrichous (distributed over the entire cell); monotrichous (a single flagellum at one pole); or amphitrichous (flagella at both poles of the cell).

Phototaxis refers to the ability of microorganisms to __________. a)survive under adverse conditions b)attach to solid surfaces c)move toward or away from chemical stimuli d)move toward a source of light. e)move in a wavelike motion

d)move toward a source of light.

Chemotaxis refers to the ability of microorganisms to __________. a)survive under adverse conditions b)escape phagocytosis c)attach to solid surfaces d)move toward or away from chemical stimuli e)move in a wavelike motion

d)move toward or away from chemical stimuli

Gram-negative cells contain a periplasmic space that is __________. a)a site of endocytosis b)filled with lysozyme c)the site of protein synthesis d)rich in degradative enzymes e)abundant in teichoic acid

d)rich in degradative enzymes

Spherical bacteria that divide and remain attached in chainlike patterns are called __________. a)spirochetes b)staphylococci c)tetrads d)streptococci

d)streptococci