What is shotgun sequencing?

• A. A method that sequences large sections of DNA at once
• B. A technique for assembling small genome pieces using a computer
• C. A procedure for analyzing proteins directly from cells
• D. A system that maps the structure of chromosomes

Answer: (B)

Shotgun sequencing is a revolutionary method used in genomics to sequence large stretches of DNA by randomly breaking it into smaller fragments and then assembling those fragments into a complete sequence. The technique involves fragmenting the DNA, sequencing the short pieces, and subsequently using computational tools to piece together the overlapping sequences to reconstruct the original long strand of DNA.

The approach's naming stems from the analogy of shooting a shotgun, where the shotgun pellets scatter across a wide area, representing the random fragmentation of DNA. This method is particularly effective for large genomes because it allows for comprehensive data collection and rapid sequencing, enabling researchers to decode complex genetic information efficiently.

The other options pertain to different aspects of genetic research: one describes sequencing methods focusing on larger sections, another addresses protein analysis, and the last refers to chromosome mapping, which do not capture the essence of shotgun sequencing. Thus, recognizing the role of computational assembly of small genome pieces illustrates the accurate understanding of how this sequencing method functions in practice.