Which of the following is true of red blood cells? a. they have multiple nuclei b. once created in bone marrow, they circulate for our lifetime c. they live for only 120 days d. they live for only about 20 days

C. They live for only 120 days

Explanation:

Well, not exactly 120 days but they live for about 100-120 days. red blood cells are also called erythrocytes. Unlike other cells, they do not have a nucleus. The red blood cells circulate through the body for about 100 to 120 days and are eventually recycled. Their main function is to carry oxygen to the different parts of the body.

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.'

not: both offer magnification to the atomic level.