Definition. Region in San Francisco, California that is considered to be the technology hub of the United States. The region is made up a number of computer companies and computer chip manufactures. The region gets its nickname from the silicon that is used in computer chips.Due to the demand for space in Silicon Valley, real estate and other property is very expensive and hard to find.he region is made up a number of computer companies and computer chip manufactures. The region gets its nickname from the silicon that is used in computer chips. Due to the demand for space in Silicon Valley, real estate and other property is very expensive and hard to find.
A substitution is a mutation that exchanges one base for another (i.e., a change in a single chemical letter such as switching an A to a G). Such a substitution could: 1  change a codon to one that encodes a different amino acid and cause a small change in the protein produced. 2  For example, sickle cell anemia is caused by a substitution in the beta-hemoglobin gene, which alters a single amino acid in the protein produced.
Answered by The Community. Making the world better, one answer at a time. A point mutation, or single base substitution, is a type of mutation that causes the replacement of a single base nucleotide with another nucleotide of the genetic material, DNA or RNA.One can categorize point mutations as follows: Transition mutations are about an order of magnitude more common than transversions.nswered by The Community. Making the world better, one answer at a time. A point mutation, or single base substitution, is a type of mutation that causes the replacement of a single base nucleotide with another nucleotide of the genetic material, DNA or RNA.