Consider statements about biotechnology: 1. PCR can amplify a specific DNA sequence. 2. Gel electrophoresis separates DNA fragments by size. 3. Restriction enzymes join DNA fragments. Which are correct? MCQ with Answer and Explanation

Polymerase Chain Reaction (PCR) is a powerful technique used to exponentially amplify a specific segment of DNA using primers and a thermostable DNA polymerase. Gel electrophoresis is a method used to separate DNA, RNA, or protein molecules based on their size and charge by applying an electric field through a gel matrix. Restriction enzymes are molecular scissors that cut DNA at specific sequences; DNA ligase is the enzyme that joins DNA fragments together. Thus, statements 1 and 2 are correct.