ABSTRACT
The fundamental blueprint for any cell or organism is encoded in its genetic material, its deoxyribonucleic acid (DNA). The linear order of bases in a segment of DNA is termed its DNA sequence and determines its function. A gene is a segment of DNA whose sequence directly determines its translated protein product. Molecular biology makes extensive use of the DNA-modifying enzymes employed by cells during replication, translation, repair, and protection from foreign DNA. Recombinant DNA technology affords biologists the capability to manipulate and analyze DNA sequences. Many of the techniques employed take advantage of a basic property of DNA, the molecular complementarity of the two strands of the double helix. Cloning is a recombinant procedure that has two main purposes: First, it allows selection of a single DNA fragment from a complex mixture, and second, it provides a means to store, manipulate, propagate, and produce large numbers of identical molecules having this single ancestor.
