Classification and Morphology of Microorganisms Flashcards
Name the five kingdoms of life.
Plantae
Fungi
Animalia
Protista
Monera
What are the two domains of life?
Eukaryotes
Prokaryotes
Which of the five kingdoms are part of the eukaryote domain?
Plantae
Fungi
Animalia
Protista
Which of the five kingdoms are part of the prokaryote domain?
Monera
What is the principle different between eukaryotes and prokaryotes?
The presence of a nucleus in a eukaryotic cell and its absence in a prokaryotic cell
Besides the presence/absence of a nucleus, what main difference is there between eukaryotes and prokaryotes.
Eukaryotic cells have a series of complex membrane-enclosed organelles which are absent in prokaryotic cells
What is the name of the third recently discovered domain?
Archaea
What are archaea?
4
Organism that looks and functions like bacteria - some bacterial genes
Shares some genes with eukaryotes
Some completely unique genes
They were the first form of life on earth
What is the order of names/titles used to systematically categorise something?
(8)
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
What is the fundamental rank in bacterial classification?
Species
What is a species?
A group of closely related organisms
In microbiology, what considers two organisms to be of the same species?
If their hereditary material is greater than 70% identical
What does a scientific name of an organism consist of?
Both its genus and species names
Give the name of the main bacteria in the colon.
Escherichia coli
What is the genus of Escherichia coli?
Escherichia
What is the species of Escherichia coli?
Coli
How must the scientific name of an organism be typed?
In italics, using a capital for the first letter of the genus
How can a scientific name be abbreviated?
By referring to the genus with a capital letter
e.g. E.coli
Where do most organisms get their names from in microbiology?
(4)
The scientist that first reported it
The location of the organism
The associated disease
The morphology
List the six main parts of a bacterial cell.
Cytoplasm
Chromosome
Ribosomes
Plasmid
Cytoplasmic membrane
Cell wall
What organelles does a eukaryotic cell have that a bacterial cell doesn’t?
(7)
Endoplasmic reticulum
Nucleus
Nucleolus
Nuclear membrane
Golgi apparatus
Mitochondrion
Chloroplast
(also has cytoplasmic membrane, cytoplasm, ribosomes)
How big are bacterial cells?
About 1-5 microns (um)
And about 1 um wide
How small are viruses?
0.25-0.025 um
How big are eukaryotic cells?
10 um but some can several hundred um long
List the six main advantages to a bacteria for being small.
Rapid growth rate
Accelerated cellular metabolism
Nutrients and waste products pass more readily into and out of a small cell
Develop large cell populations - high rate of mutations
Adapt readily to changing environmental conditions
Evolve rapidly
What are the 3 forms of bacteria?
Bacilli
Cocci
Spirochetes (rigid) or spirilla (flexible)
Name four different arrangements of cocci
Diplococci - two in groups
Tetrads = four or eight in groups
Streptococci - chains
Staphylococci - cocci in clusters
Give an example of a diplococci bacteria.
Neisseria gonorrhoeae
What disease does neisseria gonorrhoeae cause?
Gonorrhoeae
Give an example of a streptococci bacteria.
Streptococcus pyogenes
What disease does streptococci pyogenes cause?
Boils
Give an example of a staphylococci bacteria.
Staphylococcus aureus
What disease does staphylococcus aureus cause?
Boils
Give an example of a tetrad bacteria.
Micrococcus luteus
What disease does micrococcus luteus cause?
It is rarely pathogenic
Name four dyes commonly used to stain bacteria.
Methylene blue
Crystal violet
Safranin
Carbol fuchsin
How do dyes stain bacteria?
Dyes have a positive charge and are attracted to the overall negative charge of bacterial cells
What are differential stains?
Allow us to differentiate between bacterial cells based on dye colours
Name one differential staining technique.
The gram stain
What two groups does the gram stain divide bacteria into?
Gram negative (pink)
Gram positive (purple)
List the five main steps in gram staining.
Fixation
Crystal violet
Iodine
Alcohol
Counter stain with carbol fuchsin
