Module One: introduction Flashcards
Eukaryotic
“true nucleus” - organized membrane (chromosomes) surrounded by nuclear membrane.`
Prokaryotic
lack an organized nucleus, no membrane, single circular chromosome.
What are the micro-organisms from largest to smallest, describe them as well.
largest- 1. Protozoa: unicellular, nucleus. Eg. ameba or giardia
- Fungi: not photosynthetic, ridge cell wall, nucleus. Eg. yeast
- Bacteria: unicellular, no organized nucleus. Eg. Staphylococci, streptococci
smallest- 4. Viruses: small, only replicate in living host cells. EG. HIV, chicken pox
Bacteria are assigned to a kingdom and then into smaller groups. Name the groups from largest to smallest and give a description. Hint: King David Came Over For The Good Spaghetti
K - King - Kingdom: procaryotae
D - David - Divisions/Phylum: four divisions
C - Came - Class: from one to three classes in each division
O - Over - Order: several orders within each class
F - For - Family: uses the ending -aceae
T - The- Tribe: only used where there are a large number of bacteria in one family; uses the ending -eae
G - Good - Genus (singular), Genera (plural)
S- Spaghetti - Small: species
Define Species, break down into smaller groups (Genus, Tribe, Family)
Population of cells with similar characteristics.
Genus - group of closely related species
Tribe - group of related genera
Family - group of related genera or tribes
Define: Type Strain
reference specimen for the species.
Define: Subspecies
minor differences from the type strain, usually biochemical or serological characteristics that differ. Eg. Ecoli is a type of normal gut bacteria.
Define the subspecies - Biotype (biovar)
distinguished by biochemical or physical properties.
Eg. Lactose negative E.coli, most strains are lactose positive.
Define the subspecies - Serotype (serovar)
distinguished by distinctive antigenic or serological properties.
Eg. E.coli 0157:H7 agglutinates in specific antisera
Explain nomenclature (the Binomial/Linnaean system).
Two words:
Genus (capitalized) followed by species (non capitalized)
Both of them are underlined or italicized.
Eg. Clostridium tetani but italicized or underlined.
Define the Key System
When bacteria shapes and gram staining were utilized. Genetically unrelated species were placed in the same genus. -since many have been renamed and reclassified.
What is the composition of DNA?
DNA (deoxyribonucleic) has four bases: - nucleic acid
- Guanine-Cytosine that pair up
- Adenine-Thymine that pair up
What does base composition do for bacterial DNA?
It determines the percentage guanine-cytosine (G+C) in the bacterial DNA. Base composition is a fixed property.
Closely related species have similar G+C content BUT same G+C content may not be same bacteria, sequence of bases not same.
Explain nuclei acid hybridization.
When two DNA strands are separated into single strands by heat, then they are combined and cooled and hybridization (re-uniting) occurs with unknown bacterial strands if they are identical. The degree to which they hybridize is related to the similarity between the bacteria.
Explain numerical taxonomy.
Using morphology and biochemical properties, G+C content ect. with the aid of computers.
