A researcher is annotating a newly- sequenced chromosome that they constructed from contigs sequenced from a sample of Antarctic ice. The cell/organism that the chromosome came from is not known, however it yielded a single circular chromosome. You are asked to run a BLAST search to help this researcher identify the most related organism in GenBank. What would be the best strategy?
A) Perform many careful one- by- one comparisons between the newly- discovered DNA sequence and species selected from GenBank, one at a time.
B) Look for an exact match to the whole chromosome.
C) Look for a nearly identical match to a very small part (20- 40 bp) of the chromosome from all known ice bacteria.
D) Use several ~1000bp portions of the DNA sequence to search for the closest matches from among the entire available database.
E) Compare the most unusual portion of this newly- discovered chromosome to al known animal genomes.

Question

Quizplus · Accepted Answer

Using several ~1000bp portions of the DNA sequence for BLAST searches allows for a broad yet detailed comparison across the entire database, increasing the likelihood of finding the closest matches and identifying the most related organism. This approach balances specificity and coverage better than the other options.

A Researcher Is Annotating a Newly- Sequenced Chromosome That They