5. How do lichens arrive in a barren landscape, and how do they grow on rock?

I can’t answer how lichens arrive in a barren landscape but I can answer the 2nd part

Lichens grow when exposed to water. When wet, lichens begin to photosynthesize.

a. suckling by young

b. hypothalamus

c. dopamine

d. trh

e. anterior pituitary

f. mammary glands

g. milk production

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.