Using radioactively labeled DNA probes in studies of heredity makes it possible for a scientist to:
A. produce clones with DNA from two different species.
O B. make many more copies of a target gene with PCR.
O C. cause new mutations that will not add variation to a species.
OD. study the inheritance of traits that are not seen as a phenotype.

the answer to your question is b

a community that experiences major changes undergoes progress

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

the fossil record provides evidence of a common ancestor to many species.