Which of the following is an example of commensalism?

a) birds feed off the flies that swarm around the buffalo

b) a rabbit population is the main source of food for a certain fox population

c) in their attempt to obtain nectar from blooms, bees pollinate a population of flowers

d) ticks can attach and live on the blood of bison

A) Birds feed off the flies that swarm around the buffalo  

Commensalism is a relationship between individuals of two species in which in which only one species obtains benefit and another one receives neither harm nor benefit. Birds feed off the flies that swarm around buffalo is an example of commensalism because birds are getting food as flies that swarm around the buffalo. The buffalo is neither harm nor benefited by this act.

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)

a = executive branch; b = judicial branch