Which of the following is an example of symbiosis? a. barnacles living on a whale’s skin b. a tree obtaining nutrients from the soil c. phytoplankton absorbing the sun’s rays d. a blue whale feeding on zooplankton

a. barnacles living on a whale’s skin

Explanation:

Symbiosis is a interaction which occurs between two different species. In this interaction the organisms may get benefit, harm or may not be affected. Barnacles and whales are interconnected by commensalism symbiotic relationship. In this relationship the one species receives the benefit without causing any harm to other.  

Barnacles feed by attaching themselves to the back of the whales where they eat the microorganisms and the whale remains unaffected.

when it is at an intermediate population density