| Date | May 2017 | Marks available | 6 | Reference code | 17M.3.HL.TZ1.12 |
| Level | Higher level | Paper | Paper 3 | Time zone | Time zone 1 |
| Command term | Explain | Question number | 12 | Adapted from | N/A |
Question
Explain how BLAST searches are carried out and the applications of different types of these searches.
Markscheme
Process (max [5]):
a. BLAST «Basic Local Alignment Search Tool» search enables comparison of an unknown sequence with databases of sequences
b. «software» finds similar sequences / aligns sequences by locating matches between two sequences
c. carries out statistical calculations «to find matches with other sequences»
d. BLASTn used to align/show similarities in nucleotide sequences in nucleic acids
e. BLASTp used to align/show similarities in amino acid sequences in proteins
f. used to identify the gene of a protein
Application (max [2]):
g. one application of BLAST
h. second application of BLAST
eg BLAST can be used for identifying species / locating domains / establishing phylogeny / DNA mapping / other verifiable examples
