Chapter 17 Flashcards
filaments
threads
motile
capable of independent movement
flagella
whip-like tails that often occur in pairs
Genetic recombination is often facilitated by
pilli, or minute tubes
Eukaryotic cells
- Have a nuclear envelope
- Have 2 to hundreds of chromosomes per cell; DNA is double stranded
- have membrane bound organelles
- Have 80S ribosomes
- Have asexual reproduction by mitosis
- Have sexual reproduction by fusion
Prokaryotic cells
- Lack a nuclear envelope
- Have a single, closed loop of double stranded DNA plus (usually) several to 40 plasmids
- Lack membrane bound organelles
- Have 70S ribosomes
- Have asexual reproduction by fission
- Sexual reproduction unknown
conjugation
a plasmid and/or part of the DNA strand is transferred from a donor cell to a recipient cell usually through a tiny, hollow tubelike pilus.
transformation
a living cell acquires fragments of DNA released by dead cells into the medium in which It occurs and incorporates them into its own cell
transduction
fragments of DNA are carried from one cell to another by viruses
Cocci (singular: coccus)
spherical (sometimes elliptical) shaped bacteria
Bacilli (singular: bacillus)
rod shaped or cylindrical
spirilla (singular: spirillum)
helix or spiral shaped
gram positive
purple
gram negative
pink
heterotrophic
organisms that cannot synthesize their own food and therefore depend on other organisms for it
autotrophic
capable of synthesizing organic compounds from simple inorganic substances
chemoautotrophic
capable of obtaining the energy they require from various compounds or elements through chemical reactions
compost
a dark fluffy material that enriches soil. Is made of organic decomposing substances
Modes of access of disease bacteria
- air
- contamination of food or drink
- direct contact
- wounds
- insect bites and other organisms
Koch’s Postulates (definition)
rules for proving that a particular organism is the cause for a particular disease
Koch’s Postulates (4 parts)
- the microorganism must be present in all cases of the disease
- the microorganism must be isolated from the victim in pure culture
- When the microorganism from the pure culture is injected into a susceptible host organism, it must produce the disease in the host
- the microorganism must be isolated from the experimentally infected host and grown in pure culture for comparison with that of the original culture
bioremediation
the study of the use of living organisms in the cleanup of toxic wastes and pollution
