CMB1003/L05 Bacterial Genomes

Question 1

How are genes organised in bacteria?

Answer 1

Into operons

Question 2

Name 2 common mobile genetic elements.

Answer 2

Plasmids
Bacteriophages
Transposons
Integrons

Question 3

What is a trasposon/insertion sequence? (3)

Answer 3

‘Jumping genes’
Hop in and out of chromosomes and plasmids
Often carry resistance genes

Question 4

What is an integron?

Answer 4

Can pick up and accumulate ‘useful’ genes

Question 5

What is a core genome?

Answer 5

‘Housekeeping’ genes possessed by all strains of a species

Question 6

What is an accessory genome? (2)

Answer 6

Includes ‘mobile elements’ of different origins
Vary between strains of a species

Question 7

What is the pangenome?

Answer 7

Totality of the genes across different isolates of a species

Question 8

What are pathogenicity islands?

Answer 8

Clusters of genes of ‘foreign’ appearance present only in certain strains and correlated with virulence

Question 9

Describe the work of Fredrick Sanger (1977).

Answer 9

Sequenced first human mitochondrial genome

Question 10

Describe Sanger sequencing. (3)

Answer 10

Denature
Amplify with modified bases (ddNTP)
Sequencing

Question 11

Describe Illumina sequencing. (3)

Answer 11

Library preparation
Cluster amplification
Sequencing with fluorescently labelled nucleotides

Question 12

Give 2 methods of completing genome assembly.

Answer 12

Compare with known sequence
Oxford Nanopore (long read sequencing)

Question 13

Give 3 uses of sequencing in infectious disease.

Answer 13

Determine whether epidemics are local
Track spread of disease
Origin of new vaariants

Question 14

Define metagenomics.

Answer 14

The study of genetic material recovered directly from environmental samples