Week 10 / Microbiology 2

Question 1

what is biological systematics?

Answer 1

Studies how life changes through time and how living things
relate to one another

Question 2

what is taxonomy?

Answer 2

define systems by shared characteristics

Question 2

what is classification ?

Answer 2

arrange organisms into groups

Question 3

What is nomenclature?

Answer 3

assign names

Question 4

What are biological entities?

What are they split into?

Answer 4

basically every plant , animal , bacteria

cellular: Eukarya, Bacteria, Archea

Acellular: viruses , prions

Question 5

Describe the development of classification systems ?

Answer 5

Linnaeus: 2 kingdoms/ vegetablia , animalia 1735

Haeckel: 3 kingdoms / protista /plantae / anamalia 1866

chatton : 2 empires / prokaryota , eukaryota 1925

whittaker : 5 kingdoms / monera, protista,plantae,fungi,animalia 1969

woese: 3 kingdoms / bacteria , archaea,eucarya 1977

Question 6

What are viruses and prions described as?

Answer 6

anomalous entities
Non-living
Viruses are parasitic (require hosts and Viruses are parasitic (require hosts and
resources to reproduce)

Question 7

How are viruses classified?
(acellular)

Answer 7

Baltimore or ictv
but generally on the phenotype and nucleic acid

Question 8

What are prions ?
How do they cause disease?

Answer 8

Misfolded proteins

By causing proteins to fold in the brain

Question 9

examples of species Eukaryota and bacteria?

Answer 9

H.sapiens
E.coli

Question 10

What is a species?

Answer 10

A group of living organisms capable of interbreeding, even if
geographically isolated;geographically isolated

Question 11

What is strain ? in the context of microbiology

Answer 11

is a genetic variant or subtype of a bacterial species
that varies slightly from other members of the same species

Question 11

What is species ? in the context of microbiology

example

Answer 11

collection of strains that share stable properties
but differ significantly from other groups of strains but differ significantly from other groups of strains

Question 12

What are the different criteria used to assign species or strains in microbiology? [3]

Answer 12

Phenotype: an organism’s observable characteristics or traits (e.g: an organism’s observable characteristics or traits (e.g
morphology, development, biochemical or physiological properties)morphology, development, biochemical or physiological properties)

Serotype: distinct variations in cell surface antigens within a species:

Genotype:is the part of the genetic makeup of a cell, which is the part of the genetic makeup of a cell, which
determines one of its characteristics

Question 13

How can species be phenotypically classified ? [7]

Answer 13

Morphology
** Cell shape (bacilli or cocci)Cell shape (bacilli or cocci)
** Cell structure (gram staining)Cell structure (gram staining)

Biochemistry
** Enzyme production
** Transport proteins activity

** Life cycle
Vegetative or spore forming

Ecological niche
Temperature
Thermophile
Psychrophile

Interactions with other organisms

Susceptibility to bacteriophages

Pathogenicity (ability to cause disease)

Question 14

What is a serotype

Answer 14

distinct variations in cell surface antigens within a species

Question 15

What is a genotype?

How can species be genotypically classified ? [3]

Answer 15

part of the genetic makeup of a cell which determines one of its characteristics (phenotype)

Genomics
** PCR
** Amplification of selected region of interest (specific genes)

Base composition (%G/C)

Nucleic acid sequencing
** 16S rRNA
** Used in phylogenetics due to
slow rate of evolution
phylogenetics due to slow
rate of evolution
**Can also be used in diagnosis
** Whole genome sequencing

Question 16

what is a way we can define bacteria species ?

Answer 16

if genome sequences are at least 95% identical

Question 17

what can taxonomy based on genetics be confused by?

Answer 17

horizontal gene transfer

Question 18

What is vertical transmission?
What is horizontal transmission ?

Answer 18

passage of genetic information from parent to offspring

the acquisition of genetic information by transfer from an organism that is not its parent

Question 19

What is genome sequencing?

How can we characterise with this information

Answer 19

determines the complete DNA sequence of an organism at a single time

Presence/absence of genes
Gene mutations
Point mutations (SNPs)
Can change protein encoding

Gene insertions/deletions
Acquired genes from horizontal transfer

Phylogenetics

Question 20

What is phylogenetics?
How can we use it to classify?
To make it easier what is the results converted to?

Answer 20

the study of evolutionary relationships among biological entities (within species)

Produces clusters (clades) of similar organisms based on DNA or protein sequences

For 2 or more sequences, multiple sequence alignments (MSA can be produced)

More closely related = more similar the genetic sequences

percentages

Question 21

What are phylogenetic trees?

What is the rooted tree?

What is the unrooted tree?

Answer 21

visualise evolutionary relationships between organisms

the tree where each time it branches it assumes the branch is the common ancestor

only how each leaf relates to others (no inference on ancestry)

Question 22

CHECK BIOSAFETY IN POWERPOINT PLEASSEEEE

Answer 22

CHECK BIOSAFETY IN POWERPOINT PLEASSEEEE