Question

Which one of them show symbiotic relationship with man?

• A. Paramecium
• B. Trypanosoma
• C. Leishmania
• D. Escherichia coli

Answer 1

The correct option is D Escherichia coli

Escherichia coli is a bacterial species which are commonly present in the intestine of the humans. These act as non-pathogenic species which are present as commensals in the human gastrointestinal tract. This association between the bacterium and humans is known as mutualism or symbiotic association in which neither is harmed. Both the organisms are benefitted as these bacteria prevent the colonisation of other bacteria and human gut provides shelter to the bacterium.

Thus, the correct answer is option D.