Question

Each restriction enzyme cleaves a molecule only at ______.

Options

• methyl groups

• the ends of genes

• the time of DNA replication

• a particular nucleotide sequence

Answer 1

Each restriction enzyme cleaves a molecule only at a particular nucleotide sequence.

Explanation:

Restriction enzymes, also known as restriction endonucleases, act as “molecular scissors” that recognise and bind to very specific DNA sequences called recognition sites. These recognition sites are typically short palindromic sequences (reading the same forward and backwards on complementary strands). Once the enzyme identifies its unique target sequence, it cleaves the phosphodiester bonds of the DNA’s sugar-phosphate backbone. This high level of specificity allows scientists to precisely cut DNA at predictable locations for genetic engineering and research.