NEET BIOLOGY

Detailed explanation-1: -Gene duplication (or chromosomal duplication or gene amplification) is a major mechanism through which new genetic material is generated during molecular evolution. It can be defined as any duplication of a region of DNA that contains a gene.

Detailed explanation-2: -Evolution by gene duplication is an event by which a gene or part of a gene can have two identical copies that can not be distinguished from each other. This phenomenon is understood to be an important source of novelty in evolution, providing for an expanded repertoire of molecular activities.

Detailed explanation-3: -A gene is a stretch of DNA that contains the instructions for making or regulating a specific protein. Genes that make proteins are called protein-coding genes. In order to make a protein, a molecule closely related to DNA called ribonucleic acid (RNA) first copies the code within DNA.

Detailed explanation-4: -Listen to pronunciation. (tran-SKRIP-shun) In biology, the process by which a cell makes an RNA copy of a piece of DNA.

Detailed explanation-5: -A nested gene is a gene whose entire coding sequence lies within the bounds (between the start codon and the stop codon) of a larger external gene. The coding sequence for a nested gene differs greatly from the coding sequence for its external host gene.