A food handler notices that a cutting surface has developed a slimy layer after being left out overnight. Which term best describes this microbial community?

• A. Colony
• B. Plasmid
• C. Biofilm
• D. Spore

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the context of the problem. The cutting surface has developed a slimy layer, which indicates the presence of a microbial community that adheres to the surface.
2. Step 2: Review the definitions of the given terms: 'Colony' refers to a visible cluster of microorganisms growing on a solid medium; 'Plasmid' is a small, circular DNA molecule within bacteria; 'Spore' is a resistant form of some bacteria or fungi; 'Biofilm' is a structured community of microorganisms attached to a surface and embedded in a self-produced extracellular matrix.
3. Step 3: Recognize that a slimy layer on a surface is characteristic of a biofilm, where microbes produce extracellular polymeric substances that create a protective and adhesive matrix.
4. Step 4: Eliminate options that do not fit the description: a colony is typically visible on agar plates, plasmids are genetic elements not visible as layers, and spores are individual resistant cells, not layers.
5. Step 5: Conclude that the term 'Biofilm' best describes the slimy microbial community observed on the cutting surface.