What substances does lichen and moss produce that will break down rock? 1.) soil
2.) acid
3.) rust
4.) ice

5) these are organisms where the genetic material is not bound by a nucleus. they are usually unicellular.

6. in the dna double helix, how are the two strands of dna held together? a. chemical bonds between base pairs hold the two strands of dna together. b. hydrogen bonds between the base pairs hold the two strands of dna together. c. hydrogen bonds between sugar groups and phosphate groups hold the two strands of dna together. d. chemical bonds between sugar groups and phosphate groups hold the two strands of dna together.

In the african savanna, more wildebeests are born than the environment can support. which is most likely to happen over a period of years as a result