Taxonomy

Question 1

What is the largest bacteria and how large is it?

Answer 1

Thiomargarita namibiensis. It is 100-300um in diameter (micrometers)
it is visible with the naked eye

Question 2

at what size can the naked human eye no longer see bacteria

Answer 2

anything smaller than 100um

Question 3

how large is the typical bacterial cell?

Answer 3

1-2um x 4-6um

Question 4

What are the three parts of Taxonomy? explain each

Answer 4

Classification: arranges organisms into groups called Taxa
Nomenclature: assigning names to taxa
Identification: determination of a taxon to which an isolated organism belongs

Question 5

what is a species?

Answer 5

The species is the basic taxonomy unit. A collection of strains that that share many stable properties and differ a lot with other groups of strains. Species are not defined by interbreeding since bacteria reproduce asexually.

Question 6

What is a Type Strain?

Answer 6

the strain by which all other members of a species are compared too.

Question 7

How is the type strain identified??

Answer 7

Usually it is the first strain discovered for a particular species and therefore it is often not the most representative strain for that species. (after further discovery)

Question 8

What is the binomial system of Linnaues?

Answer 8

latinized italicized naming system for bacteria

Question 9

What is the general order of the animal kingdom?

Answer 9

From most specific to least

Species - genus - family - order

Question 10

In the name E. Coli

what is E and what is coli?

Answer 10

Escherichia is the genus and coli is the species

Question 11

what is Phenetic classification?

Answer 11

Based on genotype and phenotype. Looks at physical traits of organisms. This is limited for bacteria because many look very similar

Question 12

because phenetic classification based on what organism look like is limited, what other things can we look at do differentiate them?

Answer 12

How they behave / what they do.
do they have motility? what temperature do they live in? pH? what do they eat? We can also look at their % G + C content of their genome

Question 13

What is % G + C genome content?

Answer 13

Two closely related organisms are expected to have similar GC% content. NOT a similar %GC content of DNA means 2 microorganisms are closely related

Question 14

Can phenetic classification reveal evolutionary characteristics?

Answer 14

Yes, but it is not dependent on phylogenetic analysis

Question 15

What is phylogenetic classification?

Answer 15

Aka phyletic
differentiates bacteria on the basis of evolutionary development. Usually does this by comparing genetic material and gene products. Molecular data is the best indication of bacterial relationships.

Question 16

What is a Semantide?

Answer 16

a biological macromolecule that carries phylogenetic information about evolutionary history. Often proteins and nucleic acids have been used for this. The sequence of them change with time without destroying the function of them.

Question 17

How do semantides show evolutionary change?

Answer 17

When you compare the sequence of a semantide between organisms, Organisms that separated long ago in evolution will have many more differences on pattern.

Question 18

What molecules is now used as a semantide and why?

Answer 18

Semantides need to have a known structure and function, need to be conserved with time, and have a large number of monomers. 16sRNA has all of these! furthermore it has 1500 nucleotides.
16sRNA in bacteria = 18sRNA in eukaryotes

Question 19

Who was Carl Woese?

Answer 19

He discovered the 3rd domain of life known as Archaea with 16sRNA semantide

Question 20

What is Woese’s Tree?

Answer 20

Life falls into one of 3 categories 
1) eukaryotes 
2) Bacteria
3) Archaea
2 and 3 are prokaryotes
this is still debated though

Question 21

What are Whittaker’s 5 kingdoms of life?

Answer 21

Plantae
animalia
monera
fungi
protista

Question 22

What is the significance of the Monera domain?

Answer 22

they are unicellular prokaryotes which lack a well defined nucleus and organelles. typically use photosynthesis for energy

Question 23

What is the 3 main differences between bacteria and archaea?

Answer 23

1) Bacteraia have peptidoglycan / Murein layer and archaea do not !!!
2) Bacterias lipids are ester based, archaea are ether based
3) RNA subunits are 4-8 in bacteria and 8-12 in archaea!
they both have 70s ribosomes and no nucleus

Question 24

True or false, Archaea are resistant to most antibiotics

Answer 24

True

Question 25

What are the main groups of Archaea?

Answer 25

Extremophiles, thermophiles etc

Question 26

why is evolution now though of as more of a web rather than a tree?

Answer 26

Horizontal gene transfer has occurred between the domains of life creating many in between species.

Question 27

Who said, “The role of the infinitely small in nature, is infinitely large”?

Answer 27

Louis pasteur

Question 28

when did microorganisms exist on earth, how did they survive?

Answer 28

4 billion years ago
they were anaerobes ( don’t need O2)
then oxygen atmosphere developed because CyanoBacteria invented photosynthesis

Question 29

What invented photosynthesis? Why do plants have it now?

Answer 29

Bacteria invented it.

Chloroplasts domesticated cyanobacteria in a symbiotic relationship.

Question 30

What domesticated mitochondria?

Answer 30

Purple Bacteria. 16sRNA prove that mitochondria and chloroplasts once existed as bacteria

Question 31

What is the “Final say of Microbial Taxonomy”?

Answer 31

Bergeys Manual

Question 32

Explain bergeys manual

Answer 32

it describes a few thousand bacteria and archaea
each year for the past 5 years over 100 genera and 600 species are discovered!!
It used to be phenetic but now mainly by 16sRNA