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

Verified step by step guidance

1. Step 1: Understand the function of each microbial structure mentioned in the options. The glycocalyx is primarily involved in adherence, helping bacteria stick to surfaces.
2. Step 2: Recognize that pili are hair-like structures mainly used for attachment and conjugation (a form of genetic exchange), not reproduction. Reproduction in bacteria typically occurs by binary fission, which does not involve pili.
3. Step 3: Know that the cell wall provides structural support and protection to the cell, but it is not a source of toxins. Some bacteria produce toxins, but these are usually secreted proteins, not components of the cell wall itself.
4. Step 4: Confirm that the plasma membrane controls the transport of substances into and out of the cell, maintaining homeostasis.
5. Step 5: Based on these functions, identify which pair is mismatched by comparing the described function with the known role of the structure.

Key Concepts

Glycocalyx and Adherence

The glycocalyx is a sticky, gelatinous layer surrounding some bacterial cells that helps them adhere to surfaces and form biofilms. This structure plays a key role in attachment and protection against environmental threats.

Pili and Reproduction

Pili are hair-like appendages on bacterial cells primarily involved in attachment and conjugation (gene transfer), not reproduction. They facilitate DNA exchange but do not directly cause bacterial cell division.

Cell Wall Functions

The bacterial cell wall provides structural support and protection against osmotic pressure. While some cell wall components (like endotoxins in Gram-negative bacteria) can act as toxins, the primary role of the cell wall is maintaining cell shape and integrity.