Read the following passage carefully and answer the given questions.
Polymerase Chain Reaction
PCR stands for Polymerase Chain Reaction. In this reaction, multiple copies of the gene of interest is synthesised in vitro using two sets of primers and the enzyme DNA polymerase. The enzyme extends the primers using the nucleotides provided in the reaction and the genomic DNA as template. If the process of replication of DNA is repeated many times, the segment of DNA can be amplified to approximately billion times, i.e., 1 billion copies are made. Such repeated amplification is achieved by the use of a thermostable DNA polymerase, which remain active during the high temperature induced denaturation of double stranded DNA. The amplified fragment if desired can now be used to ligate with a vector for further cloning.
PCR is used for amplification of -
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → DNA
The passage says that PCR makes multiple copies of the gene of interest, using primers, DNA polymerase and the genomic DNA as template. A gene is a piece of DNA, so PCR amplifies DNA.
(1) DNA — Correct. DNA polymerase copies DNA again and again, so the DNA segment is amplified.
(2) RNA — Incorrect. RNA is not copied by DNA polymerase.
(3) Protein — Incorrect. Proteins are made by translation, not copied by PCR.
(4) Lipid — Incorrect. Lipids carry no genetic information and cannot be copied.
Note: This passage is taken from NCERT as it is. Most CUET (UG) questions come straight from NCERT, so study the book line by line, including figures and their titles.