Microbiology Quiz Chapter 4

Why are mycoplasmas resistant to antibiotics that interfere with cell wall synthesis?

• They are considered viruses

• They have no cell wall

• Since they are the smallest known bacteria, antibiotics can't affect them

• Their sterols containing plasma membranes protect them

Here are some characteristics about prokaryotic and eukaryotic cells.

• Prokaryotic cells don't have their DNA enclosed within a nucleus

• Eukaryotes DNA is not associated with histones while prokaryotes DNA is consistently associated with those chromosomal proteins

• Archaea contain pseudomurein cell walls

• Prokaryotes divide by binary fission while eukaryotes divide by mitotic spindle

• Cell walls of prokaryotes contain many nutrients like polysaccharides

• B and E are false

• B, C and E are false

• None is false

______, external to the cell wall, it is composed of polysaccharide and/or polypeptide. Can be described as either a capsule or a slime layer. It is also a very important component of ______. 

We can find bacteria in multiple sizes, shapes with multiple functions as prokaryotic cells. Find which ones fit their nature. (can pick more than one)

• Bacteria that come in spheres and remain attached in chainlike patterns are called streptococci

• The basic shapes of bacteria are coccobacillus, tetrads and spirochete

• A rod-shaped bacterium is called bacillus

• Staphyloccoci are associated with grapelike clusters or broad sheets

• Cocci can be oval, elongated, round, or flattened on one side

• Some environmental conditions can alter the shape of a bacterium

• Spiral bacteria can be either straight or twisted

• A bacterium with an intermediate shape between a coccus and a bacillus is called coccobacillus

The endosymbiotic theory explains that _______ originates from ___________, meaning that larger bacterial cells lost their _____ and engulfed smaller bacterial cells.

Chose whatever is true about the movement of materials across membranes.

• Active processes mean the cell must uses ATP energy to move substances from area of low concentration to areas of high concentration (with the concentration gradient)

• Passive processes mean that substances cross the membrane from an area of high concentration to an area of low concentration without any use of ATP energy by the cell

• Simple diffusion, facilitated diffusion and osmosis are parts of active processes

• Simple diffusion and facilitated diffusion involve integral proteins

• Simple diffusion is used especially with the transportation of small molecules across their cell membrane

• Osmotic pressure is the pressure required to prevent the movement of pure water into a solution containing some solutes

• Osmosis is the net movement of solvent molecules across a selectively permeable membrane from an area with a high concentration of solvent molecules to an area of high concentration of solvent molecules

• Group translocation occurs exclusively in prokaryotes.

• When group translocation occurs, the substance is chemically altered during transport across the membrane, making the plasma membrane impermeable to the altered substance so it'll remain inside the cell.

All but one is true to glycocalyx's functions. Which are false? (can pick more than one)

• Slime layer can contribute to bacterial virulence

• Capsules can protect viruses from phagocytosis by the cells of the host.

• Can protect a cell against dehydration

• A glycocalyx's viscosity will enhance the movement of nutrients out of the cell

• None is false