PlanetofProkaryotesLEC20 Flashcards
How old is the first found amber that contain an ancient spider attack fossil?
100 million year old
What are the two kingdoms early classification systems had?
Plants & Animals
What replaced the old classification system? What are they split into? By who?
A 3 domain system: -Archaea -Bacteria -Eukarya Each one is split into many kingdoms by taxonomists.
What is a virus?
A microsopic, noncellular infectious particle that attack every kingdom of life. They do have DNA & can evolve.
In a hand full of soil, is the number of living prokaryotes greater or less than the number of people who ever live?
Greater
Where can prokaryotes thrive?
Almost everywhere, including extreme conditions.
Most prokaryotes are what? What do they remarkably have?
Unicellular
Genetic diversity
Prokaryotic cells have cell walls, and have variety of what?
Shapes.
Common shapes are spherical, rod-shaped, and spiral.
What is a fimbriae, and what does it do for prokaryotes?
Hairlike structures that allow prokaryotes to stick to their substrate or other individuals in a colony.
What is a flagella, and what does it do for most motile bacteria?
Tail-like structure similar to a sperm’s tail. It helps them propel themselves.
Many prokaryotes can move, but others can what?
Grow toward or away from stimuli in the way plants do.
How do prokaryotes reproduce?How often do they divid?
Quickly by binary fission. If conditions are good, they divid every hour.
What shape do DNA have in prokaryotes?
A long ring.
Some also have smaller rings of DNA called plasmids that can be considered independant life-forms similar to viruses.
What can horizontal gene transfer do for prokaryotes?
Speed up their evolution.
When one bacterium obtain resistence, it can quicky transfer those genes to many species of bacteria.
What can prokaryotes form, which can remain viable in harsh conditions for centuries?
Endospores
What are the 4 mode of nutrition found in prokaryotes?
photoautotrophs
chemoautotrophs
photoheterotrophs
chemoheterotrophs
Explain Photoautotrophs
Prokaryotes that feed themselves by using light to make food.
Explain Chemoautotrophs
Prokaryotes that feed themselves by extracting energy from chemicals.
Explain Photoheterotrophs
Prokaryotes that feed themselves by using light to make food, and consuming organisms.
Explain Chemoheterotrophs
Prokaryotes that feed themselves by consuming chemicals or other organisms.
What are obligate aerobes?
Prokaryotes that require oxygen.
What are obligate anaearobes?
Prokaryotes that are poisoned by oxygen.
What are faculative anaerobes?
Prokaryotes that can survive with or without oxygen.
What do some prokaryotes that live inside plants roots do to fertilizes plants?
They fix atmospheric nitrogen into the soil.
What are the 2 largest groups of bacteria?
Proteobacteria and gram-positive bacteria. Dyed blue.
What do Archaea share some traits with? What don’t they seem to do compared to prokaryotes?
Bacteria & Eukaryotes.
They don’t seem to cause disease.
They don’t form spores.
What does it mean for some Archaea to be extreme thermophiles?
They thrive in very hot environment.
What does it mean for some Archaea to be extreme halophiles?
They thrive in high saline (salty) environments.
Where do Methanogens (Archaea) live, what do they produce, and how do they contribute to that environment?
Swamps and marshes.
They produce methane as a waste product.
Recycle dead organisms to provide nutrients for others.
