BLAST Query and Analysis Concepts

This video tutorial by Svenja Lohner from Science Buddies introduces the BLAST tool from NCBI, explaining how to access and use it for genomic research. It covers different BLAST options, navigating the query page, setting search parameters, and understanding the results. The tutorial also explains how to create phylogenetic trees and perform pairwise sequence alignments, providing a comprehensive guide to using BLAST for genomic analysis.

What does BLAST stand for?

• Basic Linkage and Search Technique

• Basic Local Alignment Search Tool

• Biological Local Alignment Search Technique

• Biological Linkage and Search Tool

Which BLAST option is useful for determining evolutionary relationships?

• Local Align

• Nucleotide BLAST

• Protein BLAST

• Global Align

What input format is NOT accepted by the BLAST query page?

• PDF file

• Uploaded sequence file

• FASTA format

• Accession number

What is the purpose of the 'Job Title' box on the BLAST query page?

• To select the database

• To choose the BLAST program

• To enter the query sequence

• To name your search

Which BLAST program is used for identifying nucleotide sequences?

• blastp

• blastx

• megablast

• blastn

Which tab in the BLAST report provides a graphical overview of alignments?

• Description

• Graphic Summary

• Alignments

• Taxonomy

What does an E-value represent in the BLAST report?

• The number of identical sequences

• The number of expected hits by chance

• The percentage of query coverage

• The maximum identity score

What feature allows you to analyze evolutionary relationships in BLAST?

• Distance tree

• Local alignment

• Global alignment

• Query coverage

What is the difference between local and global alignment in BLAST?

• Local alignment is faster than global alignment

• Global alignment is only for protein sequences

• Local alignment compares parts of sequences, global alignment compares entire sequences

• Local alignment compares entire sequences, global alignment compares parts

What is the purpose of the 'Align two or more sequences' option in BLAST?

• To filter results by organism

• To perform a global alignment of two sequences

• To perform a local alignment of two sequences

• To compare a query sequence with multiple databases