To prove a yeast is dimorphic, which test is performed?

To prove a yeast is dimorphic, which test is performed?

• A. Incubate yeast subculture at 37C
• B. Incubate yeast subculture at 4C
• C. Grow in anaerobic conditions
• D. Stain with Gram stain

Answer: (A)

Dimorphism in fungi means the organism can switch between two forms depending on temperature: mold form at environmental temperatures and yeast form at body temperature. To demonstrate this capability, you induce the organism to express the yeast form by incubating it at 37°C, which is close to human body temperature. If the yeast subculture shows yeast-like morphology or budding at this temperature, it supports the organism’s dimorphic nature. Storing or growing at 4°C won’t reliably reveal the switch to yeast and may simply slow growth. Anaerobic conditions or Gram staining don’t test the temperature-driven morphologic change, so they don’t demonstrate dimorphism.

Dimorphism in fungi means the organism can switch between two forms depending on temperature: mold form at environmental temperatures and yeast form at body temperature. To demonstrate this capability, you induce the organism to express the yeast form by incubating it at 37°C, which is close to human body temperature. If the yeast subculture shows yeast-like morphology or budding at this temperature, it supports the organism’s dimorphic nature. Storing or growing at 4°C won’t reliably reveal the switch to yeast and may simply slow growth. Anaerobic conditions or Gram staining don’t test the temperature-driven morphologic change, so they don’t demonstrate dimorphism.