1.Most are unicellular
2. Very small, typical diameter of 0.5-5 um
3. Prokaryotic cells have a variety of shapes
4. Prokaryotes are well organized
100
How has horizontal gene transfer affected the evolution of prokaryotes?
Over hundreds of millions of years, prokaryotes have acquired genes from even distantly related species. There are significant portions of the genomes of many prokaryotes are actually mosaics of genes imported from other species.
100
What are Protists?
Protists are a large and diverse group of eukaryotic microorganisms, which belong to the kingdom Protista.
100
Describe conjuction
DNA is transferred between two prokaryotic cells that are joined.
200
Describe the structure of a virus
It is an infectious particle consisting of nucleic acid enclosed in a protein coat and, for some viruses, surrounded by a membranous envelope.
200
Describe the cell-surface structure of bacteria
1. Most bacterial walls contain peptidoglycan.
2. The cell wall of many prokaryotes is surrounded by a sticky layer of polysaccharide or protein- this layer is the capsule, if it is dense and well-defined.
3. Some prokaryotes stick to their substrate or one another by fimbriae.
4. Pili- appendages that pull two cells together prior to DNA transfer.
200
What is a extremophile?
extremophiles are lovers of extreme conditions.
extreme halophiles live in highly saline environments
extreme thermophiles live in very hot environments
200
Describe the cytoskeleton
Extends throughout the cell and provides the structural support the enables eukaryotic cells to have asymmetric forms, as well as to change shape as they move, feed, and grow.
200
What is the role of oxygen in metabolism of prokaryotes?
1. Obligate aerobes must use oxygen for cellular respiration and cannot grow with out it.
2. Obligate anaerobes are poisoned by oxygen.
3.Anaerobic respiration is a form of respiration using electron acceptors other than oxygen. Although oxygen is not used as the final electron acceptor, the process still uses a respiratory electron transport chain; it is respiration without oxygen.
4. Facultative anaerobes-use oxygen if it is present, but can also carry out fermentation or anaerobic respiration in an anaerobic environment.
300
What is a host range
The limited number of host species a virus can infect.
300
Describe the difference between gram-positive bacteria and gram-negative bacteria.
Gram-positive bacteria has a thick layer of peptidoglycan and just one plasma membrane. During the gram staining process the peptidoglycan traps the crystal violet which masks the safranin dye.
Gram-negative bacteria has a thin layer of peptidoglycan that is found between the outer membrane and the plasma membrane. During the gram staining process the crystal violet easily washes away, revealing the red safranin dye.
300
What do chemoheterotrophic prokaryotes do?
They function as decomposers, breaking down dead organisms as well as waste products thereby unlocking supplies of carbon, nitrogen, and other elements.
300
What is endosymbiosis?
It is a relationship between two species in which one organism lives inside the cell or cellls of another organism.
1. Attachment
2. Entry of phage DNA and degradation of host DNA
3. Synthesis of viral genomes and proteins
4. Self-assembly
5. Release
400
Describe the internal organization of and DNA of Bacteria
1.The genome of the prokaryote is structurally different from a eukaryotic genome and in most cases has considerably less DNA.
2.Chromosomes are circular.
3.Lack a nucleus
4.Chromosomes are located in the nucleiod.
5. Contain plasmids.
6. Ribosomes are slightly smaller
400
Name a few prokaryotic ecological interactions
Mutuallism
Commensalism
Parasitism
400
How is the clade Excavata characterized?
It is characterized by its cytoskeleton.
Some members have an excavated feeding groove
This group includes the diplomonads, parabasalids and euglenozoans
400
How is Archaeplastida characterized?
It is comprised of land plants, red algae and green algae.
500
Explain lysogenic Viruses
1. The Phage injects its DNA
2. Phage DNA circularizes
3. Phage DNA integrates into bacterial chromosome
4. Prophage is copied with bacterial chromosome
5. Many cell divisions create many infected bacteria.
6. Daughter cell with prophage
7. Prophage exits chromosome
500
What is the difference in transformation and transduction?
In transformation the genotype of a prokaryotic cell is altered by the uptake of foreign DNA from its surroundings.
In transduction, phages carry prokaryotic genes from oe host cell to another.
500
What are endotoxins?
Endotoxins are lipopolysaccharide components of the outer membrane of gram-negative bacteria. Endotoxins are released only when the bacteria die and their cell wall breaks down.
500
How is the SAR clade characterized?
It is a highly diverse group of protists defined by DNA similarities.
Includes Diatoms, Golden algae, Brown algae, Dinoflagellates, Apicomplexans, Ciliates, Forams, Cercozoans and Radilarians.
500
How are Unikonts characterized?
Unikonts include protists that are closely related to fungi and animals
Include Slime Molds, Tubulinids, Entamoebas, Nucleariids, Fungi, Choanoflagellates, and Animals