Consider statements about biotechnology: 1. Restriction enzymes cut DNA at specific sites. 2. PCR is used to amplify DNA. 3. Gel electrophoresis separates proteins by size. Which are correct? MCQ with Answer and Explanation

Restriction endonucleases act as molecular scissors, cleaving DNA at specific palindromic recognition sequences. Polymerase Chain Reaction (PCR) is a technique used to amplify specific DNA segments exponentially. Gel electrophoresis is primarily used to separate DNA or RNA fragments based on size, though it can separate proteins (SDS-PAGE), the statement implies it's exclusively or primarily for proteins in general biotech context, but 1 and 2 are definitively core facts. Let's refine: Gel electrophoresis separates charged molecules; for DNA it's by size. Statements 1 and 2 are universally correct core principles.