Which of the following best describes the abundance of Batrachochytrium dendrobatidis (Bd) on a frog's skin following exposure to Bd?

• A. Bd abundance decreases immediately after exposure due to immune response.
• B. Bd is never detected on the skin after exposure.
• C. Bd abundance remains constant regardless of exposure duration.
• D. Bd abundance typically increases over time as the fungus colonizes the skin.

Answer: (D)

Verified step by step guidance

1. Understand the biology of Batrachochytrium dendrobatidis (Bd), a chytrid fungus that infects amphibian skin by colonizing and growing on it.
2. Recognize that upon exposure, Bd spores attach to the frog's skin and begin to develop into mature fungal structures, leading to an increase in fungal cells over time.
3. Consider the host immune response: while the frog's immune system may attempt to combat the fungus, Bd often proliferates initially before any significant immune-mediated reduction occurs.
4. Evaluate the typical infection dynamics, where Bd abundance on the skin increases as the fungus grows and spreads, rather than decreasing immediately or remaining constant.
5. Conclude that the best description is that Bd abundance typically increases over time following exposure, reflecting fungal colonization and growth on the frog's skin.