[Campbell Biology P.641] A species of bacterium lives in the human large intestine, obtainin... | Practice Question

A species of bacterium lives in the human large intestine, obtaining nutrients from undigested food and sometimes causing inflammation or disease if it overgrows. How would this bacterium primarily be classified in terms of its ecological relationship with humans?

  • A: Commensalist.
  • B: Decomposer.
  • C: Gut mutualist.
  • D: Symbiotic pathogen.

Explanation

A pathogen is an organism that causes disease. Symbiosis refers to any close and long-term biological interaction between two different biological organisms. Since this bacterium lives in the intestine a symbiotic relationship and can cause disease, it is classified as a symbiotic pathogen.