when athletes are tested for evidence of performace enhancing drugs, two urine samples are usually taken. One sample is tested and the other sample is stored. Why must one be stored?

answer; ///i believe that the correct answer is (a) specialized cells)

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.

ans.

dna fingerprinting is defined as a process that determines the dna characteristics of an individual. these dna characteristics are unique among individuals as their fingerprints, so it is known as dna fingerprinting.

steps of dna fingerprinting includes extraction of dna from sample, amplification of dna, restriction digestion of amplified dna, and then analysis of dna by gel electrophoresis, respectively.

thus, the next step performed by the scientist is 'to cut the amplified dna (obtained by polymerase chain reaction) by restriction enzymes that cleave the dna into fragments and their analysis.'