symbiosis

What is mutualism?

Both partners benefit (e.g., synthesis of vitamins K and B).

What is commensalism?

One partner benefits, the other unharmed (flora on skin).

What is parasitism?

Microbe benefits at host’s expense → pathogenic infection.

Where is normal flora found?

On every body part exposed to the outside world;

exceptions: deep lungs, stomach.

What is the difference between transient and resident flora?

Transient = temporary;

Resident = permanent population.

Can normal flora ever cause disease?

Yes—opportunistic pathogens such as E. coli may cause UTIs.