Evolution

Question 1

The start?

Answer 1

Anoxic conditions with anaerobic metabolism.

Chemolitotrophic - chemoorganotrophic - phototrophic

Ex. H2S + CO2 -> S

Question 2

Then what?

Answer 2

The great oxidation event

H2O + CO2 -> CO2 + O2

The high reduction potential of O2/H2O couple which has provided higher energy yield and then higher reproduction.

Fe2+ + O2 –> Fe3+ ore

Question 3

Stromatophiles?

Answer 3

Fossilized microbial formations

Question 4

Tree of life?

Answer 4

Based on the 16S rRNA seqs where ~ 60 genes are shared

Question 5

Mitochondria?

Answer 5

Alphaproteobacterium + prokaryote

Question 6

Chloroplast?

Answer 6

Cyanobacterium into early eukaryot

Question 7

In common?

Answer 7

Ribosomes, 16S rRNA seq and circular DNA

Question 8

Horizontal gene transfer?

Answer 8

Benefical genes transfered rapidly in the early forms of life and traits became assigned to each group. Provided genetic, physiological and structural differences.

Genes from archae and bacteria provided translation, transcription and metabolic genes.

Question 9

Hyphosesis?

Answer 9

Several endosymbiosis
Symbiogenesis
Hydrogen hyphosesis

Question 10

RNA-processing?

Answer 10

RNA splicing and separation between ribosomes and nucleus

Question 11

Evolution?

Answer 11

Change in allele frequence in a population that over time resulted in descent with modification.

Question 12

Cause of genetic variation?

Answer 12

Mutation
Recombination
Selection
Genetic drift

Question 13

Mutations?

Answer 13

Random change in DNA that accumulate over time and is the driving source of evolution as a source of natural variation.

A new trait can have a selective advantage if environment changes. Mutations still occur but the trait will dissapear since it is not favoured by selection.

Question 14

Recombination?

Answer 14

Rejoining of parts of DNA that generates new combinations.

Question 15

Selection?

Answer 15

Based on fitness and selects for the reproduction of those organisms with mutations that provide a higher fitness advantage.

Question 16

Genetic drift?

Answer 16

Cause gene frequency to change over time. Evolution in the abscence of natural selection.

Question 17

Bottleneck events?

Answer 17

Reduced population size that then regrows.

Question 18

Strains?

Answer 18

Genetic subtype or variant of a microorganism, ex. E. coli.

Question 19

Core or PAN or both?

Answer 19

Core genome -> shared by all strains of a species.

Pan genome –> Core and Pan genome but not shared by all strains of the organism. Acquired by horizontal gene transfer.

Question 20

Systematics?

Answer 20

Polyphasic approach -> phylogenetic species concenpt

Question 21

Why are there Differences in DNA?

Answer 21

Function of mutations that have accumulated since the strains shared a common ancestor.

Changes can be estimated homologous nuvleotide positions and then through seqs alignment.

Question 22

Homoplasy?

Answer 22

Convergent evolution. Shared trait not from a common ancestor.

Question 23

Phylogenetics concenpt?

Answer 23

Strains that share traits, cohesive genetic material and share a reason common ancestor

Question 24

DNA-hybridization?

Answer 24

Probe and target DNA –> % of probes that hybridize to target DNA and similarity in ssu rRNA.

Question 25

Difference @ species level?

Answer 25

ssu rRNA
RecA
GyrB

Question 26

MLST?

Answer 26

Housekeeping genes with essential functions on the same chromosome. Similiar seq for a gene, allele number and 2 strains have the same allelic profile.

Question 27

Genome fingerprinting?

Answer 27

Eva. between samples of a species

Question 28

Polymorphism?

Answer 28

> 2 changes in differences of morphs or forms, even as phenotypes.

Question 29

Ribotyping?

Answer 29

For identification of bacteria. As rRNA in a microbial genome have a high [] feature of all sums and bands.

Question 30

Phenotypic analysis?

Answer 30

FAME -> between gram- bacteria

Question 31

Proof-readers?

Answer 31

IJSEM - new taxa

ICDP - review

Question 32

Summary?

Answer 32

Berkleys manual

The prokaryotes