Liches, mosses, grasses and annual flowers, bushes and shrubs, trees. Primary succesion is a type of succesion occuring in an environment. This is a gradual growth of ecosystem from an area without vegatation. This can happen from simple to a more complex organism. The pioneer plants are usually the hard organism that can strive at aharsh condition and gradually shifting to a more adapted to less harsh conditions.
Nucleoside analogs are the mutagenic chemicals that have a structure that is similar to the normal bases of the nucleotide and thus can be incorporated in the DNA during the process of replication, however as it has different base-pairing rules than the normal nucleotide base it can lead to mutations.
An example of a nucleoside analog is acyclovir which an analog of guanosine.
