What does the term “basic unit of matter” refer to?

The term " basic unit of matter" refers to an atom.

The atom consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus  contains a mix of positively charged protons and electrically neutral neutrons  except in the case of hydrogen which is considered the only stable nuclide with no neutrons.

The electrons of an atom are bound to the nucleus by electromagnetic force. Two or more atoms can be bound to each to form a molecule.

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."

c: warm water flows from the western tropical pacific toward south america. that should be the right answer! hope it .