| Date | November 2017 | Marks available | 1 | Reference code | 17N.3.HL.TZ0.10 |
| Level | Higher level | Paper | Paper 3 | Time zone | TZ0 |
| Command term | Outline | Question number | 10 | Adapted from | N/A |
Question
The table shows a comparison of DNA base sequences in several yeast (Saccharomyces) genomes.
[Source: P. F. Cliften et al. (2001) ‘Surveying Saccharomyces Genomes to Identify Functional Elements by Comparative DNA Sequence Analysis’, Genome Research, 11, pp. 1175–1186. © Cold Spring Harbor Laboratory Press. Reproduced with permission.]
Identify the species that has the lowest percentage of coding sequences.
State how similar nucleotide sequences can be identified.
The yeast Saccharomyces cerevisiae was the first eukaryotic organism to have its entire genome sequenced. Suggest reasons for the choice of yeast as a study organism.
Outline possible medical applications of the polymerase chain reaction (PCR).
Markscheme
S. unisporus
BLASTn/sequence alignment software
“n” required in BLASTn
a. easy to grow
OR
easy/cheap to produce large amounts
OR
fast generation time
b. genomes are small/easy to manipulate
c. metabolically diverse
d. industrial applications/biopharming
e. no ethical issues «with yeast»
[Max 3 Marks]
a. identify different viral/influenza strains
b. genetic testing/testing for genetic disease mutations
c. tissue typing
d. vaccine development
[Max 1 Mark]
