Barnacles live on whales. whales carry the barnacles around, which the barnacles feed. the whales are unaffected. this is an example of predation mutualism parasitism commensalism

The correct answer for the blank is-

commensalism.

Commensalism is a long term biological interaction between two organisms belonging to different species where one organism gets benefit and the other organism neither gets benefit nor it is harmed.

In this question, Barnacles living on whales get benefit as they get their food while moving around on Whales. In this interaction, the whales are unaffected.

Thus, this is an example of commensalism.

image result for how many calories of energy will 20 grams of carbohydrates provide in one gram provides 4 calories

consuming the right balance of protein, carbohydrates and fat can you maintain a healthy weight and optimize your energy levels. protein and carbohydrates both contain 4 calories per gram, while fat provides 9 calories per gram.

a physical change is being made.