[Campbell Biology P.637] According to the text, how does B. thetaiotaomicron benefit its hum... | Practice Question

According to the text, how does B. thetaiotaomicron benefit its human host?

  • A: It directly produces essential vitamins for the host.
  • B: It helps activate human genes to build intestinal blood vessels and induces cells to produce antimicrobial compounds.
  • C: It eliminates all other competing bacterial species in the gut.
  • D: It secretes an exotoxin that neutralizes harmful pathogens.

Explanation

The first paragraph of the text states: 'Signals from the bacterium activate human genes that build the network of intestinal blood vessels necessary to absorb nutrient molecules. Other signals induce human cells to produce antimicrobial compounds to which B. thetaiotaomicron is not susceptible. This action may reduce the population sizes of other, competing species, thus potentially benefiting both B. thetaiotaomicron and its human host.'