Ch. 16 The Origin & Evolution of Microbial Life: Prokaryotes And Protists Flashcards
Stromatolites
Rock formed of layered fossilized bacterial mats
- Made Earth aerobic w/ the O2 produced → aerobic life
Spontaneous Generation
nonliving things produce life (wrong)
Biogenesis
“All life today, including microbes, arises only by the reproduction of pre-existing life”
- Louis Pasteur
What did Stanley Miller and Harold Urey do?
Showed that organic molecules could be generated on lifeless Earth from the abundant energy sources and high UV radiation
What did Sidney Fox do?
Founded that there are specific enzymes or dilute solution of organic monomer dipped on hot rock/clay → heat vaporizes water → concentrates monomer and bonds
“The essential difference between life and non life is replication.” means what?
Nucleic acids that replicate and store genetic info.
Ribozymes
an enzymatic RNA molecule that catalyzes chemical reactions
RNA World
a hypothetical period in the evolution of life when RNA served as a rudimentary genes and the sole catalytic molecules
Why are prokaryotes important?
Essential for decomposing dead organisms and returning vital chemical elements to the environment
What are the 2 domains of prokaryotes?
Bacteria and Archaea
What are characteristics of bacteria domain?
RNA sequences are unique / polymerase is small/simple
Introns absent / Antibiotic sensitivity inhibited
Peptidoglycan present
Membrane lipid, carbon chains unbranched
What are characteristics of archaea domain?
RNA sequence match eukaryotic / polymerase complex
Introns present in some / antibiotic sensitivity not inhibited
Peptidoglycan absent
Membrane lipids, carbon chains branched
Peptidoglycan
A polymer of complex sugars cross linked by short peptides; a material unique to eubacterial cell walls
What are the 3 varieties of prokaryotes?
1) cocci
2) bacilli
3) spirilli
Autotroph
an organism that makes its own food, thereby sustaining itself w/o eating others (inorganic → organic)
Chemoautotroph
an organism that obtains both energy and carbon from inorganic chemicals’ makes its own organic compounds from CO2 w/o using light energy
Photoautotroph
An organism that obtains energy from sunlight and carbon from CO2 by photosynthesis
Heterotrophs
an organism that cannot make its own organic food molecules and must obtain them by consuming other organisms/products; consumer/decomposer in food chain
Photoheterotrophs
an organism that obtains energy from sunlight and carbon from organic sources
Chemoheterotrophs
an organism that obtains energy and carbon from organic molecules
Prokaryotic Flagellum
a long surface projection that propels a prokaryotic cell thru its liquid environment; totally different from the flagellum of a eukaryotic cell
Pili
short projections on the surface of prokaryotic cells that help prokaryotes attach to other surfaces; specialized sex pili are used in conjugation to hold mating cells together
Endospore
a thick-coated, protective cell produced w/in a bacterial cell exposed to harsh conditions
Actinomycetes
one of a group of bacteria characterized by a mass of branching cell chains (filaments)
Cyanobacteria
Photosynthetic, oxygen producing bacteria, formerly called blue-green algae
- lakes, ponds, tropical oceans
Pathogen
A disease causing organism
Exotoxins
a poisonous protein secreted by eubacteria
Endotoxins
a poisonous component of the cell walls of certain bacteria (glycolipids)
- Fever, aches, drop in blood pressure
Lyme disease
a debilitating human disease caused by bacteria Borella burgdorferi; characterized by a red rash at the site of tick bite and if not treated heart disease, arthritis, and nervous disorders
Koch’s Postulates
a set of criteria used to establish that a particular infectious agent causes a disease
What are Koch’s Postulates? (4)
- The same, specific pathogen must be identified in each animal (host) that has the disease.
- The pathogen must be isolated from a host and grown in a pure culture, one in which no other kinds of cells are present.
- The original disease must be produced in experimental hosts that are inoculated w/ pathogen from pure culture.
- The same pathogen must be isolated from experimental hosts after the disease develops in them.
What are the 2 processes that allowed for eukaryotes to evolve from prokaryotes?
1) Membrane Infolding
2) Endosymbiosis
Membrane Infolding
eukaryote’s endomembrane system developed from the inward folds of the plasma membrane of a prokaryote
Endosymbiosis
a process by which the mitochondria and chloroplasts of eukaryotic cells probably evolved, from symbiotic associations b/w small prokaryotic cells living inside larger ones
Symbiosis
a close association b/w organisms of 2+ species
Protozoan
a protest that lives primarily by ingesting food; a heterotrophic, animal-like protist
Flagella
a protist (protozoan) that moves by means of 1+ flagella
Amoebas
a type of protist characterized by great flexibility and the presence of pseudopodia
Pseudopodia
a temporary extension of a amoeboid cellular functions in moving cells and engulfs food
Apicomplexans
one of a group of parasitic protozoans, some of which cause human disease (complex organelles)
Ciliates
a type of protozoan that moves be means of a cilia and common in aquatic environments
- 2 types of nuclei…macronucleus and micronuclei
Cellular slime molds
a type of protist that has unicellular amoeboid cells and multicellular reproductive bodies in its life cycle
Plasmodial slime mold
a type of protist that has amoeboid cells, flagellated cells, and an amoeboid plasmodial feeding stage in its life cycle
Plasmodium
A single mass of cytoplasm containing many nuclei
- the amoeboid feeding stage in the life cycle of a plasmodial slim mode
Algae
One of a great variety of protists, most of which are unicellular or colonial photosynthetic autotrophs w/ chloroplasts containing the pigment chlorophyll a; heterotrophic and multicellular protists closely related to unicellular autotrophs are also regarded as algae
Dinoflagellates
a unicellular photosynthetic alga w/ 2 flagella situated in perpendicular grooves in cellulose plates covering the cell
Diatoms
a unicellular photosynthetic alga w/ a unique, glassy cell wall containing silica
Green Algae
one of a group of photosynthetic protists that includes unicellular, colonial, and multicellular species; plantlike in having biflagellated cells (gametes in colonial/multicellular), chloroplasts w/ chlorophyll a, cellulose cell walls, and starch
Brown Algae
One of a group of marine, multicellular, autotrophic protists, the most common and largest type of seaweed
Red Algae
one of a group of marine, mostly multicellular, autotrophic protists, which include reed building coralline algae
Kelp
A giant brown algae, up to 100 m long, that forms extensive undersea forests
Alteration of Generation
A life cycle in which there is both a multicellular diploid form, the sporophyte, and a multicellular haploid form, the gametophyte; a characteristic of plants and multicellular green algae
Gametophytes
a multicellular haploid form in the life cycle of organisms undergoing alternation of generations; mitotically produces haploid gametes that unite and grow into sporophyte generation
Sporophyte
the multicellular diploid form in the life cycle of organisms undergoing alternation of generations; results from a union of gametes and meiotically produces haploid spores that grow into the gametophyte generation
