Question

question 2 of 10
why did the invention of pcr make dna fingerprinting possible?
a. pcr made it possible to produce enough copies for reliable tests.
b. pcr allows genes to produce the insulin protein.
c. pcr eliminates the need to use gel electrophoresis.
d. pcr produces mrna instead of dna, which is more reliable.

Explanation:

PCR (Polymerase Chain Reaction) is a technique that amplifies DNA. DNA fingerprinting requires a sufficient amount of DNA for analysis. Before PCR, the amount of DNA available (e.g., from a crime - scene sample) was often too small. PCR allows for exponential amplification of specific DNA regions. This amplification provides enough DNA copies so that techniques like gel electrophoresis (which is still used in DNA fingerprinting, so option C is wrong) can be reliably performed. Option B is about gene expression (producing insulin protein) which is not related to DNA fingerprinting. Option D is incorrect as PCR amplifies DNA, not mRNA.

Answer:

A. PCR made it possible to produce enough copies for reliable tests.