Question

a fungus and an alga form a mutualistic symbiosis to make a lichen. the fungus gets food from the alga and the alga gets a place to live. lichens are able to grow on bare rock and help contribute to soil formation. as a result, they are often the first species to colonize a new area during primary succession. because of this, we say that lichens are a(n)...
a. founder effect
b. pioneer species
c. climax community
d. secondary succession

Explanation:

Pioneer species are the first to colonize a new area in primary succession. Lichens grow on bare rock and start soil - formation during primary succession, fitting the definition of pioneer species. The founder effect is about genetic drift in a new population. A climax community is the final stable stage of succession. Secondary succession occurs on previously colonized land.

Answer:

B. pioneer species