3. Taxonomy In Microobiology

Question 1

What’s microbial taxonomy

Answer 1

Study of microbial classification

Question 2

How does taxonomy study microorganisms?

Answer 2

From 3 points of view:
1. Systematic classification- what they are
2. Nomencalture - what’s their correct name
3. Identification- what features can describe them in a sufficiently accurate way

Question 3

What are different approaches of classification?

Answer 3

1. Phenetic- it compares phenotypic and morphological features which can be directly observed
2. Genotypic- it compares genome sequences using molecular techniques
3. Phylogenetic- organizes organisms based on their (presumed) evolutionary relationshops. This generates phylogenic trees( tree of life/ dendrograms). It integrates genotypic methods focusing on observed genetic sequences (in particular RNA)

Question 4

What’s most used part of genome in prokaryotes for genome sequencing

Answer 4

DNA encoding 16S small subunit of rRNA

Question 5

Why are rRNA ideal subjects for evolutionary studies?

Answer 5

1. They are essential
2. They have same function in all ribosomes
3. They get modified in time extremly slowly

Question 6

What are some general rules of nomenclature?

Answer 6

Scientific name is always in latin.
The name of species is written in italic, beginning with capital letter. After the first citatuon, the generic name may be abbreviated
Name has 2 parts: first (generic name) identifies the genus and second(specific name) identifies species belinging to the same genus

Question 7

How are taxonomic classification organized?

Answer 7

In hyerarchical level or Taxa. Every higher-ranked taxon includes all members of taxa linked below it

Question 8

What are some fundamental taxa(in descending order)

Answer 8

Domain
Kingdom
Phylum
Class
Order
Family
Genus- group of species with 1 or more properties in common
Species-fundamenral unit

Question 9

What are microorganism classification below species

Answer 9

-strain- genetic variant within a species of microorganisms. It comes from a single colony. When a characterized strain is used for the general definution of entire species= type strain and it cultured as a living reference model
-biovar- variant within strains, based on morphology(morphovars), antigenic properties(serovars), genomic(genovar)…

Question 10

What can be used for classification of bacteria

Answer 10

-Morphological features= dimensions, mode of motion, staining properties, macroscopic growth
-Biochemical and nutritional features= endproducts or other chemical information about cell components and metabolytes
-Ecological features
-Nucleotide composition of DNA, genetic homology and characteristics

Question 11

What some subdivisuon of taxa can be based on?

Answer 11

Staining properties
Formation of spores(spore-forming bacteria)
Oxygen recquirement
Metabolic profile

Question 12

Are there different models of tree of life

Answer 12

Yes. It’s because of reciprocal relationship between bacteria, archaea and eukaryotes

Question 13

What’s LUCA

Answer 13

Last universal common ancestor. It’s believed ir differentiated to bacteria and other branch that later differentiated into archaea and eukaryotes