Biology Quiz: Gram-Positive and Gram-Negative Bacteria

Bacterial Cell Structure and Function

• The main function of the central mesosome in Gram-positive bacteria is to protect the cell membrane from injuries.
• In Gram-negative cells, the outer membrane is more permeable than the plasma membrane because LPS is larger than most membrane phospholipids.

Bacterial Flagella

• Not all motile bacteria have flagella, but those that do can direct their movement toward a source of nutrients.
• Flagella increase in length by adding new material to the tip, not the base.
• The filaments of flagella are composed of protein subunits called flagellin.

Immunity to Viruses

• Passive immunity is a form of immunity to viruses that would be least likely to be lifelong.
• Active immunity, on the other hand, is a form of immunity that can be lifelong.

Antimicrobial Agents

• Penicillin and lysozyme are similar in that they both affect cell walls.

Viral Pathogens

• HIV has the ability to evade the immune system.
• Herpes viruses have distinct properties that characterize them.