Study Questions Ch 4 Book & Practice Test Mastering Micro

which of the following is false about fimbriae a. they are composed of protein b. they may be used for attachment c they are found on gram negative cells d. they are composed of pilin e. they may be used for motility

e

which of the following is not a distinguishing characteristic of prokaryotic cells a. they usually have a single circular chromosome b. they lack membrane enclosed organelles c. they have cell walls containing peptidoglycan d. their DNA is not associated with histones e. they lack a plasma membrane

e

You have isolated a cell with a peptidoglycan cell wall. What other structure can you safely assume the cell has? a nucleus a plasma membrane a mitochondrion a chloroplast

plasma membrane

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

a

Penicillin specifically interferes with peptidoglycan synthesis. Which of the following cells is most likely to be damaged by penicillin? gram-positive bacterial cells yeast cells human cells cells of archaea

a

Which of the following is true of bacteria that have atypical cell walls, such as those in the genus Mycoplasma? Bacteria with atypical cell walls are generally among the smallest bacteria that can reproduce outside a host cell. These atypical bacteria usually stain gram-negative. These atypical bacteria have the same plasma membrane typical of bacteria. Although small, these atypical bacteria cannot pass through most filters.

a

Which of the following pairs is matched correctly? spheroplast—gram-negative bacteria that are exposed to lysozyme but retain some of the outer membrane L form—a wall-less bacterium created by the action of lysozyme; the plasma membrane remains intact, and the cell carries on metabolism 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 protoplast—a genus of bacteria that typically do not have cell walls

a

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

a

Which of the following statements does NOT provide evidence for the endosymbiotic theory? Prokaryotes contain peptidoglycan in their cell walls. The ribosomes contained within mitochondria and chloroplasts are very similar to prokaryotic ribosomes. The same antibiotics that inhibit protein synthesis in prokaryotes also inhibit protein synthesis within mitochondria and chloroplasts. Mitochondria and chloroplasts contain circular DNA, similar to the DNA in prokaryotes.

a

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? gram-positive streptobacilli gram-positive coccobacilli gram-positive tetrads gram-negative staphylococci

a

what happens when a gram positive bacterium is placed in an aqeuous solution of lysozyme and 10% sucrose a. no change will result; the solution is isotonic b. water will move into the cell c. water will move out of the cell d. the cell will undergo osmotic lysis e. sucrose will move into the cell from an area of higher concentration to one of lower concentration

a

you have isolated a motile gram positive cell with no visible nucleus. you can assume this cell has a. ribosomes b. mitochondria c. an endoplasmic reticulum d. a golgi complex e. all of the above

a

match the structures in column a to their functions in column b a. cell wall b. endospore c. fimbriae d. flagella e. glycocalyx f. pili g. plasma membrane h. ribosomes 1. attachment to surfaces 2. cell wall formation 3. motility 4. protection from osmotic lysis 5. protection from phagocytes 6. resting 7. protein synthesis 8. selective permeability 9. transfer of genetic material

a 4 b 6 c 1 d 3 e 1, 5 f 3, 9 g 2, 8 h 7

In a prokaryotic cell, all of the following are functions of either fimbriae or pili EXCEPT __________. formation of biofilms movement attachment to a surface transfer of DNA

b

The nucleus of a eukaryotic cell differs from the nucleoid of a prokaryotic cell in all of the following ways EXCEPT which one? The prokaryotic nucleoid usually contains a single circular chromosome, whereas the eukaryotic nucleus contains multiple linear chromosomes. The prokaryotic nucleoid contains DNA combined with histones. Histones are lacking in the eukaryotic nucleus. The eukaryotic nucleus is surrounded by a nuclear envelope. There is no envelope surrounding the prokaryotic nucleoid. The eukaryotic nucleus contains nucleoli. There are no nucleoli in the prokaryotic nucleoid.

b

Which of the following bacterial structures is necessary for chemotaxis? capsules flagella metachromatic granules plasmids

b

Which of the following processes uses membrane proteins that act as channels or carriers allowing ions or large molecules to move across the plasma membrane without using energy? simple diffusion facilitated diffusion osmosis active transport

b

Which of the following statements about ribosomes is FALSE? Cells with a high rate of protein synthesis have large numbers of ribosomes. Antibiotics that interfere with protein synthesis harm both prokaryotic and eukaryotic ribosomes. Eukaryotic ribosomes are larger (80S) than prokaryotic ribosomes (70S).

b

Within the cytoplasm of bacterial cells are reserve deposits where certain nutrients accumulate. These are called __________. vacuoles inclusions lysosomes ribosomes

b

the antibiotic amphotericin b disrupts plasma membranes by combining with sterols it will affect all of the following cells except a. animal cells b. gram negative bacterial cells c. fungal cells d. mycoplasma cells e. plant cells

b

which of the following pairs is mismatched a. glycocalyx - adherence b. pili - reproduction c. cell wall - toxin d. cell wall - protection e. plasma membrane - transport

b

which statement best describes what happens when a gram negative bacterium is placed in distilled water and penicillin a. no change will result; the solution is isotonic b. water will move into the cell c. water will move out of the cell d. the cell will undergo osmotic lysis e. sucrose will move into the cell from an area of higher concentration to one of lower concentration

b

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

c

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

c

Which of the following membrane transport mechanisms takes place in eukaryotic cells but NOT in prokaryotic cells? facilitated diffusion osmosis active transport endocytosis

d

Which of the following organisms have eukaryotic cells that do NOT contain a cell wall? algae plants fungi animals

d

Which of the following statements is true? Endospores allow a cell to attach to solid surfaces and to surfaces within the host. One bacterial cell produces many endospores. Endospores are reproductive structures. Endospores are extremely durable structures that can survive high temperatures.

d

Which one of the following pairs is correctly matched? centrioles—cellular respiration lysosomes—secretion mitochondrion—cell division Golgi complex—membrane formation and secretion of proteins

d

which of the following statements best describes what happens to a cell exposed to polymyxins that destroy phospholipids? a. in an isotonic solution, nothing will happen b. in a hypotoinic solution, the cell will lyse c. water will move into the cell] d. intracellular contents will leak from the cell e. any of the above might happen

d

which statement best describes what happens when a gram positive bacterium is placed in distilled water and penicillin a. no change will result; the solution is isotonic b. water will move into the cell c. water will move out of the cell d. the cell will undergo osmotic lysis e. sucrose will move into the cell from an area of higher concentration to one of lower concentration

d