Lichens, represented by this symbiotic relationship, are responsible for the establishment of a new site for plant growth

Lichens, represented by this symbiotic relationship, are responsible for primary succession or  the establishment of a new site for plant growth.

Explanation:

Primary succession can be described as a type of succession which occurs in areas where there was no form of life before or any form of life had fully been eradicated from those areas.  For example, lava flow etc.

Lichens are the species which tend to colonize these lands first and are the pioneer species to be seen during primary succession. They have the capability to grow on rocks and release acids which break down the rocks and converts them into soil.

6.3%

explanation:

the acceptance rate for yale university is 6.3%. this means that only 6 percent of people who apply actually get accepted!