Question

Which is a step in hierarchical genome sequencing that is not found in shotgun genome sequencing?

a. fragment the genome
b. organize the clones based on their order in the genome before sequencing
c. construct a genomic library
d. assemble the sequences into contigs based on overlap

Answer 1

Hierarchical genome sequencing requires organizing the clones into the correct order before sequencing, which is not necessary in shotgun sequencing where fragments are randomly sheared and assembled based on sequence overlap. d. assemble the sequences into contigs based on overlap

Step-by-step explanation:

The step in hierarchical genome sequencing that is not found in shotgun genome sequencing is organizing the clones based on their order in the genome before sequencing. Hierarchical, or clone-by-clone, sequencing involves creating a physical map of the genome, where large DNA fragments are arranged in the correct order before sequencing.

This contrasts with shotgun sequencing, which does not require mapping of segments prior to sequencing. Instead, shotgun sequencing randomly shears DNA into smaller fragments, utilizes the chain termination method for sequencing, and relies on computer algorithms to assemble these sequences into contigs by identifying overlapping regions without prior knowledge of their position in the genome.