Mastering Ch 4

Which of the following statements is INCORRECT regarding prokaryotic cells? a. They lack membrane-enclosed organelles. b. Their DNA is not enclosed within a membrane. c. They reproduce by binary fission. d. They typically have a circular chromosome. e. They lack a plasma membrane.

A gram-positive bacterium suddenly acquires resistance to the antibiotic methicillin. This trait most likely occurred due to acquisition of new genetic information through a. binary fission. b. conjugation. c. transduction. d. meisosis. e. transformation.

Functions of the glycocalyx include all of the following EXCEPT a. binary fission. b. protection against dehydration. c. biofilm formation. d. source of nutrition. e. increased virulence.

Which structure acts like an "invisibility cloak" and protects bacteria from being phagocytized? a. cell membrane b. cell wall c. fimbriae d. slime layer e. capsule

The terms "run" and "tumble" are generally associated with a. cell wall fluidity. b. taxic movements of the cell in response to attractants or repellents. c. clustering properties of certain rod-shaped bacteria. d. cell membrane synthesis.

Fimbriae and pili differ in that a. pili are used to transfer DNA. b. pili are used for transfer of DNA and motility. c. pili are used for attachment to surfaces. d. there are only one or two pili per cell. e. pili are used for motility.

Which of the following is NOT characteristic of the glycocalyx found in bacteria? a. a viscous coating surrounding the cell made of polysaccharide, polypeptide, or both b. creates a slimy, slippery coating that prevents bacteria from attaching to surfaces c. if firmly attached, contributes to bacterial virulence d. a structure that can be visualized using an acidic negative stain and a basic counterstain

Each of the following statements concerning the gram-positive cell wall is true EXCEPT a. it is sensitive to lysozyme. b. it is sensitive to penicillin. c. it maintains the shape of the cell. d. it contains teichoic acids. e. it protects the cell in a hypertonic environment.

Which of the following statements about gram-negative cell walls is FALSE? a. They are sensitive to penicillin. b. Their Gram reaction is due to the outer membrane. c. They are toxic to humans. d. They protect the cell in a hypotonic environment. e. They have an extra outer layer composed of lipoproteins, lipopolysaccharides, and phospholipids.

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 cell wall. c. lives in an extreme environment. d. has cilia. e. has a mitochondrion.

Antibiotics that target the cell wall are an effective treatment against many pathogenic bacteria. True False

Spheroplasts, protoplasts, and mycoplasms are bacterial cells without cell walls. True False

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

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

Which of the following statements best describes what happens when a bacterial cell is placed in a solution containing 5% NaCl? a. The cell will undergo osmotic lysis. b. Water will move into the cell. c. Sucrose will move into the cell from a higher to a lower concentration. d. Water will move out of the cell. e. No change will result; the solution is isotonic.

By which of the following mechanisms can a cell transport a substance from a lower to a higher concentration? a. extracellular enzymes b. simple diffusion c. active transport d. aquaporins e. facilitated diffusion

Which of the following is NOT a typical characteristic of most bacterial plasma membranes? a. contains proteins b. composed of a phospholipid bilayer c. is selectively permeable d. contains cholesterol e. site of energy production

Which of the following statements is TRUE? a. Endospores are easily stained in a Gram stain. b. A cell produces one endospore and keeps growing. c. Endospores are for reproduction. d. A cell can produce many endospores. e. Endospores allow a cell to survive environmental changes by producing a dormant period with no growth.

Antibiotics that target cell wall synthesis ultimately cause bacterial cell death as a result of a. inhibition of molecular transport. b. cell shrinkage. c. plasmolysis. d. osmotic lysis. e. decreased synthesis of plasma membrane.

Where are phospholipids most likely found in a prokaryotic cell? a. ribosomes b. around organelles c. the plasma membrane and around organelles d. flagella e. the plasma membrane

Where are phospholipids most likely found in a eukaryotic cell? a. surrounding flagella b. the plasma membrane c. ribosomes d. the plasma membrane, around organelles, and surrounding flagella e. around organelles

In a hypertonic solution, a bacterial cell will typically osmolyze. stay the same. plasmolyze. lyse. burst.

Which of the following are NOT energy reserves? carboxysomes metachromatic granules lipid inclusions polysaccharide granules ribosomes

The DNA found in most bacterial cells a. is circular in structure. b. is linear in structure. c. is found in multiple copies. d. utilizes histones for chromosomal packaging. e. is surrounded by a nuclear membrane.

Which type of solution would cause a bacterium with a weak or damaged cell wall to burst as water moves into the cell? an isotonic solution either a hypotonic or an isotonic solution a hypertonic solution a hypotonic solution

Cells placed in a hypotonic solution tend to lose water due to osmotic pressure. True False

Endospores are a reproductive structure. True False

Which of the following structures is NOT found in some prokaryotic cells? cilium peritrichous flagella flagellum axial filament pilus

Which of the following is NOT a functionally analogous pair? a. cilia - pili b. mitochondria - prokaryotic plasma membrane c. 9+2 flagella - bacterial flagella d. chloroplasts - thylakoids e. nucleus -nucleiod region

The internal structure of eukaryotic cilia and flagella are the same. True False

Which one of the following organisms has a cell wall? L forms animal cells fungi mycoplasmas protoplasts

Which of the following statements accurately describes specific bacterial cell walls? a. The cell walls of gram-negative bacteria contain many more layers of peptidoglycan than those of gram-positive bacteria. b. In bacteria with acid-fast cell walls, the carboxylic acid in the walls forms a layer outside a thin layer of hydrophilic polypeptides. c. Gram-negative bacterial cell walls contain teichoic acids, whereas the cell walls of gram-positive bacteria do not. d. In gram-negative bacteria, the thin layer of peptidoglycan is surrounded by an outer membrane made of phospholipids, lipopolysaccharides, and proteins.

Which statement regarding the structure or function of ribosomes is correct? a. Ribosomes are found both free-floating and attached to the rough endoplasmic reticulum in eukaryotes and in prokaryotes. b. The ribosomes in the prokaryote are slightly larger than those found in the eukaryotic endoplasmic reticulum. c. In eukaryotes, the ribosomes found in chloroplasts and mitochondria are 70S ribosomes, which are similar in size to prokaryotic ribosomes. d. Ribosomes are the sites of lipid biosynthesis in both prokaryotes and eukaryotes.

Which of the following pairs is mismatched? a. lysosome digestive enzymes b. centrosome food storage c. mitochondria ATP production d. Golgi complex secretion e. endoplasmic reticulum internal transport

Which of the following organelles most closely resembles a prokaryotic cell? mitochondrion Golgi complex nucleus cell wall vacuole

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 gram-positive bacterial cells for nucleic acid isolation? mycolic acid lysozyme polymixins alcohol water

Which of the following is NOT found or observed to occur in both mitochondria and prokaryotes? binary fission cell wall ATP-generating mechanism circular chromosome 70S ribosomes

Which of the following eukaryotic organelles is correctly matched with its function? a. glycocalyx--transport b. mitochondrion--protein synthesis c. vacuole--storage of materials d. flagellum--protection

Which of the following is found in the cytoplasm of prokaryotic cells but is ABSENT from the cytoplasm of eukaryotic cells? View Available Hint(s) enzymes water a cytoskeleton DNA

Many enzymes in both prokaryotic and eukaryotic cells are compartmentalized within organelles. True False

Which of the following facts does NOT provide evidence for the endosymbiotic theory? View Available Hint(s) a. The same antibiotics that inhibit protein synthesis in prokaryotes also inhibit protein synthesis within mitochondria and chloroplasts. b. Mitochondria and chloroplasts contain circular DNA, similar to the DNA in prokaryotes. c. Prokaryotes contain peptidoglycan in their cell walls. d. The ribosomes contained within mitochondria and chloroplasts are very similar to prokaryotic ribosomes.