Question

A commensal bacterium 1. may also be an opportunistic pathogen. 2. always causes disease in its host.3. isn't capable of causing disease in its host. 4. is beneficial to its host. 5. does not receive any benefit from its host.

Answer 1

Beneficial to its host.

Step-by-step explanation:

Commensalism is a relationship when a bacterium lived in the host body, get food from the host and in return provide essential nutrients to the host. It is the beneficiary relationship.

For example, many bacteria lived in the human gut act as normal flora of the gut. These bacteria or normal flora get food from the gut and in return provide them essential vitamins and nutrients.