Microbiology Chapter 4

1) Which of the following statements is INCORRECT regarding prokaryotic cells? A) Their DNA is not enclosed within a membrane. B) They lack membrane-enclosed organelles. C) They typically have a circular chromosome. D) They reproduce by binary fission. E) They lack a plasma membrane.

2) Each of the following statements concerning the gram-positive cell wall is true EXCEPT A) it maintains the shape of the cell. B) it is sensitive to lysozyme. C) it protects the cell in a hypertonic environment. D) it contains teichoic acids. E) it is sensitive to penicillin.

3) Which of the following statements best describes what happens when a bacterial cell is placed in a solution containing 5 percent NaCl? A) Sucrose will move into the cell from a higher to a lower concentration. B) The cell will undergo osmotic lysis. C) Water will move out of the cell. D) Water will move into the cell. E) No change will result; the solution is isotonic.

4) A gram-positive bacteria suddenly acquires resistance to the antibiotic methicillin. This trait most likely occurred due to A) conjugation. B) binary fission. C) meisosis. D) transformation. E) transduction.

5) By which of the following mechanisms can a cell transport a substance from a lower to a higher concentration? A) simple diffusion B) facilitated diffusion C) active transport D) extracellular enzymes E) aquaporins

6) Which of the following is NOT a typical characteristic of most bacterial plasma membranes? A) site of energy production B) composed of a phospholipid bilayer C) contains proteins D) contains cholesterol E) is selectively permeable

7) Which of the following have a cell wall? A) protoplasts B) fungi C) L forms D) mycoplasmas E) animal cells

8) Which of the following statements is TRUE? A) Endospores are for reproduction. B) Endospores allow a cell to survive environmental changes. C) Endospores are easily stained in a Gram stain. D) A cell produces one endospore and keeps growing. E) A cell can produce many endospores.

9) Which of the following pairs is mismatched? A) endoplasmic reticulum & internal transport B) Golgi complex & secretion C) mitochondria & ATP production D) centrosome & food storage E) lysosome & digestive enzymes

10) Which of the following organelles most closely resembles a prokaryotic cell? A) nucleus B) mitochondrion C) Golgi complex D) vacuole E) cell wall

Figure 4.1 11) Which drawing in Figure 4.1 is a tetrad? A) a B) b C) c D) d E) e

12) Which drawing in Figure 4.1 possesses an axial filament? A) a B) b C) c D) d E) e

13) Which drawing in Figure 4.1 is streptococci? A) a B) b C) c D) d E) e

14) Antibiotics that target cell wall synthesis ultimately cause bacterial cell death as a result of A) osmotic lysis. B) inhibition of molecular transport. C) decreased synthesis of peptidoglycan. D) plasmolysis. E) cell shrinkage.

15) 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 lyse the bacterial cells for nucleic acid isolation? A) lysozyme B) polymixins C) alcohol D) water E) mycolic acid

16) Which of the following statements about gram-negative cell walls is FALSE? A) They protect the cell in a hypotonic environment. B) They have an extra outer layer composed of lipoproteins, lipopolysaccharides, and phospholipids. C) They are toxic to humans. D) They are sensitive to penicillin. E) Their Gram reaction is due to the outer membrane.

17) Which of the following structures is NOT found in some prokaryotic cells? A) flagellum B) axial filament C) cilium D) pilus E) peritrichous flagella

18) Functions of the glycocalyx include all of the following EXCEPT A) biofilm formation. B) increased virulence. C) source of nutrition. D) protection against dehydration. E) binary fission.

19) Which structure acts like an "invisibility cloak" and protects bacteria from being phagocytized? A) slime layer B) fimbriae C) capsule D) cell membrane E) cell wall

20) Which of the following is NOT part of the passive transport process? A) plasma membrane B) transporter proteins C) ATP D) concentration gradient E) aquaporins

Figure 4.2 21) Which of the following terms best describes the cell in Figure 4.2? A) peritrichous flagella B) amphitrichous flagella C) lophotrichous flagella D) monotrichous flagella E) axial filament

22) In bacteria, photosynthetic pigments are found in A) chloroplasts. B) cytoplasm. C) chromatophores. D) mesosomes. E) ribosomes.

23) The difference between simple diffusion and facilitated diffusion is that facilitated diffusion A) moves materials from a higher to a lower concentration. B) moves materials from a lower to a higher concentration. C) requires ATP. D) requires transporter proteins. E) does not require ATP.

24) The terms "run" and "tumble" are generally associated with A) cell wall fluidity. B) taxic movements of the cell. C) clustering properties of certain rod-shaped bacteria. D) cell membrane synthesis.

25) You have isolated a motile, gram-positive cell with no visible nucleus. You can safely assume that the cell A) has 9 pairs + 2 flagella. B) has a mitochondrion. C) has a cell wall. D) lives in an extreme environment. E) has cilia.

26) Fimbriae and pili differ in that A) there are only one or two pili per cell. B) pili are used for motility. C) pili are used to transfer DNA. D) pili are used for transfer of DNA and motility. E) pili are used for attachment to surfaces.

Figure 4.3 27) In Figure 4.3, which diagram of a cell wall is a gram-negative cell wall? A) a B) b C) both a and b D) neither a nor b E) The answer cannot be determined based on the information provided.

28) In Figure 4.3, which diagram of a cell wall possesses molecules responsible for symptoms associated with infection? A) a B) b C) both a and b D) neither a nor b E) The answer cannot be determined based on the information provided.

29) In Figure 4.3, which diagram of a cell wall has a structure that protects against osmotic lysis? A) a B) b C) both a and b D) neither a nor b E) The answer cannot be determined based on the information provided.

30) In Figure 4.3, which diagram of a cell wall is decolorized by alcohol? A) a B) b C) both a and b D) neither a nor b E) The answer cannot be determined based on the information provided.

31) In Figure 4.3, which diagram of a cell wall is resistant to many antibiotics (e.g., penicillin)? A) a B) b C) both a and b D) neither a nor b E) The answer cannot be determined based on the information provided.

32) In Figure 4.3, which diagram of a cell wall contains teichoic acids? A) a B) b C) both a and b D) neither a nor b E) The answer cannot be determined based on the information provided.

33) In Figure 4.3, which diagram of a cell wall contains porins? A) a B) b C) both a and b D) neither a nor b E) The answer cannot be determined based on the information provided.

34) Where are phospholipids most likely found in a prokaryotic cell? A) flagella B) around organelles C) the plasma membrane D) ribosomes E) the plasma membrane and around organelles

35) Where are phospholipids most likely found in a eukaryotic cell? A) surrounding flagella B) around organelles C) the plasma membrane D) ribosomes E) the plasma membrane, around organelles, and surrounding flagella

36) Which of the following is NOT found in mitochondria and prokaryotes? A) circular chromosome B) 70S ribosomes C) cell wall D) binary fission E) ATP-generating mechanism

37) Which of the following statements is correct about diffusion? A) It requires an expenditure of energy by the cell. B) It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration. C) It is an active process in which molecules move from a region of lower concentration to one of higher concentration. D) It may require a transport protein. E) It involves movement of molecules down a concentration gradient and may require a transport protein.

38) Oxygen crosses a plasma membrane A) by osmosis. B) through simple diffusion. C) with the help of a nonspecific transporter. D) through facilitated diffusion. E) through porins.

39) In a hypertonic solution, a bacterial cell will typically A) lyse. B) burst. C) stay the same. D) plasmolyze. E) osmolyze.

40) What will happen if a bacterial cell is placed in distilled water with lysozyme? A) The cell will plasmolyze. B) The cell will undergo osmotic lysis. C) Water will leave the cell. D) Lysozyme will diffuse into the cell. E) No change will result; the solution is isotonic.

41) How do spirochetes and spirilla differ? A) Spirochetes do not have a cell wall but spirilla do. B) Spirilla are found in chains of cells whereas spirochetes exist as individual cells. C) Spirilla have an external flagella but spirochetes have axial filaments. D) Spirochetes have a rigid, corkscrew shape while spirilla are helical and more flexible. E) Spirochetes and spirilla are basically the same organisms and the terms can be used interchangeably.

42) Which one of the following pairs is mismatched? A) metachromatic granules - phosphate storage B) lipid inclusions - energy reserve C) ribosomes - protein storage D) sulfur granules - energy reserve E) gas vacuoles - flotation

43) Which of the following are NOT energy reserves? A) carboxysomes B) polysaccharide granules C) lipid inclusions D) sulfur granules E) metachromatic granules

44) Which of the following is NOT a functionally analogous pair? A) nucleus -nucleiod region B) mitochondria - prokaryotic plasma membrane C) chloroplasts - thylakoids D) cilia - pili E) 9+2 flagella - bacterial flagella

45) The DNA found in most bacterial cells A) is surrounded by a nuclear membrane. B) utilizes histones for chromosomal packaging. C) is circular in structure. D) is linear in structure. E) is found in multiple copies.

1) The cell walls of bacteria are responsible for the shape of the bacteria and the difference in the Gram stain reaction.

2) Antibiotics that target the cell wall are an effective treatment against many pathogenic bacteria.

3) Cells placed in a hypotonic solution tend to lose water due to osmotic pressure.

4) Small, hydrophobic molecules pass through a cell membrane most easily by diffusion.

5) Spheroplasts, protoplasts, and mycoplasms are bacterial cells without cell walls.

6) Endospores are a reproductive structure.

7) The internal structure of eukaryotic cilia and flagella are the same.

8) Many enzymes in both prokaryotic and eukaryotic cells are compartmentalized within organelles.

9) The number of organelles such as chloroplasts, mitochondria, and rough endoplasmic reticulum is the same in all eukaryotic cells.

10) If you observe rod-shaped red cells after the Gram stain, you can assume their cell walls contain endotoxin.