Morphology and differentiation

Question 1

Gliding Myxobacteria

Answer 1

Large chromosome
Myxococcus xanthus
Complex lifecycle with vegetative and fruiting bodies
-Swarms of cells aggregate requiring intercellular communication, chemotaxis, motility
-Follow slime trails of other bacteria

Question 2

Cell surface structures -Fimbriae and common pili

Answer 2

Attachment
Allows colonisation, important pathogenic factor
Can allow evasion of a host immune response

Question 3

F Pili

Answer 3

The sex pilus, of F pilus

Allows bacterial conjugation and horizontal gene transfer

Question 4

Flagella

Answer 4

Movement - Linked to sensory system allowing chemotaxis and phototaxis

Question 5

Nano-wires

Answer 5

Recent discovery
Allows transfer of electrons either to external substrate or to another cell
Gleobacter and Shewanella species

Question 6

Bacterial endospores

Answer 6

Cortex: layers of peptidoglycan
Core: Calcium and dipicolinic acid dehydrates spore also stabilises DNA
Spore coat: made of spore proteins
Small acid soluble proteins (SASPs): bind to DNA to protect from heat and UV Carbon/energy source for germination

Question 7

Endospore examples

Answer 7

Bacillus thuringiensis - light refractive
Bacillus anthracis - purple - resistant to dyes
Bacillus spore - red

Question 8

Asymmetric division

Answer 8

Caulobacter crescentus

Question 9

Filamentation

Answer 9

a. Innate immune cues
b. Predator sensing cues
c. Quorum sensing cues
d. Antimicrobial cues

Question 10

Main divisions of protozoa

Answer 10

Sporozoa - e.g. Plasmodium in RBC
Flagellates - e.g. Trypanosoma
Amoebae - e.g. Entamoeba
Ciliates - e.g. Balantidium

Question 11

Giarda

Answer 11

Cyst –> Trophozoite

Fecal-Oral Life cycle