BISC 431 Exam 1 Questions with
Complete Solutions
Bioremediation of Uranium-Contaminated Environments - Answer--uranium
contamination of groundwater has occurred where uranium has been processed or
stored
-Some bacteria can convert (reduce) U6+ to U4+ to go from water soluble to insoluble
-uranium is contained, not removed
Bioremediation of Hydrocarbons - Answer--organic pollutant can eventually be
completely degraded to CO2 by microbes
-prokaryotes have been used in bioremediation of several major crude oil spills
Antiquity and Extent of Microbial Life - Answer--microorganisms were the first life forms
on earth to show the basic characteristics of living systems
-cyanobacteria paved the way for the evolution of other lifeforms by producing the
oxygen in earth's atmosphere
-however, long before cyanobacteria appeared on earth, the planet was already
teeming with life and diverse communities of microorganisms were widespread
Evolution and Diversity of Microbial Cells - Answer--first self-replicating entities may not
have been cells
-Last universal common ancestor (LUCA): common ancestral cell from which all cells
are descended
-first cell appeared between 3.8 and 3.7 million years ago
-atmosphere was anoxic until ~2 billion years ago
-metabolism were exclusively anaerobic until the evolution of oxygen-producing
phototrophs
-life was exclusively microbial until ~1 billion years ago
Microbes Everywhere doing nearly Everything - Answer--Deinococcus can survive 3
million rads (3,00x radiation needed to kill a person)
-Halobacterium can live at 32% salinity (~9x sea water)
-Picrophilus lives at a pH of 0.003 (acidic enough to dissolve metals)
-Natranobacterium lives at a pH of 12
-Pyrolobus lives at temperatures >113°C
-Polaromonas lives at temperatures <0°C
-Moritella lives at pressure over 1,000 atms
Robert Hooke - Answer--while it had been suspected that there were organisms that
were too small to see, they were first discovered by Robert Hooke
-created the first microscope
, Louis Pasteur - Answer--discovered that alcoholic fermentation was a biologically
mediated process
-disproved theory of spontaneous generation which led to aseptic technique
-developed vaccines for anthrax, fowl cholera, and rabies
Robert Koch - Answer--demonstrated link between microbes and infectious diseases
-developed solid media techniques for obtaining pure cultures of microbes
-observed that masses of cells have different shapes, colors, and sizes
Great Plate Count Anomaly - Answer--difference between colony counts and counts
under a microscope
-viable but nonculturable populations: when a culture of cells is stressed, then it will no
longer grow in media
-uncultured populations: These could not be grown on typical media
Evolution - Answer--the process of change over time that results in new varieties and
species of organisms
-occurs in any self-replicating system in which variation occurs as the result of mutation
and selection and differential fitness is a potential result
-thus over time, all cells and viruses evolve
Phylogeny - Answer--evolutionary relationships between organisms
-relationships can be deduced by comparing genetic information in the different
specimens
-Ribosomal RNA (rRNA) is excellent for determining phylogeny
-all cells have rRNA
-they are rarely transferred between cells
-relationships visualized on a phylogenetic tree
-phylogenetic relationships between bacteria can be deduced by comparing genetic
information
Separating Microbes into Functional Groups - Answer--phototrophs obtain energy from
light
-chemotrophs obtain energy from chemicals
-autotrophs require CO2 as a carbon source
-heterotrophs require an organic nutrient to make organic compounds
Four major Modes of Nutrition - Answer--Photoautotrophy
-Chemoautotrophy
-Photoheterotrophy
-Chemoheterotrophy
Identifying Bacteria Based on Metabolic Capacity - Answer--did a swab and then did a
bunch of metabolic tests to determine if it was a certain organism
-not used in microbial ecology because it won't be able to tell you very much
Complete Solutions
Bioremediation of Uranium-Contaminated Environments - Answer--uranium
contamination of groundwater has occurred where uranium has been processed or
stored
-Some bacteria can convert (reduce) U6+ to U4+ to go from water soluble to insoluble
-uranium is contained, not removed
Bioremediation of Hydrocarbons - Answer--organic pollutant can eventually be
completely degraded to CO2 by microbes
-prokaryotes have been used in bioremediation of several major crude oil spills
Antiquity and Extent of Microbial Life - Answer--microorganisms were the first life forms
on earth to show the basic characteristics of living systems
-cyanobacteria paved the way for the evolution of other lifeforms by producing the
oxygen in earth's atmosphere
-however, long before cyanobacteria appeared on earth, the planet was already
teeming with life and diverse communities of microorganisms were widespread
Evolution and Diversity of Microbial Cells - Answer--first self-replicating entities may not
have been cells
-Last universal common ancestor (LUCA): common ancestral cell from which all cells
are descended
-first cell appeared between 3.8 and 3.7 million years ago
-atmosphere was anoxic until ~2 billion years ago
-metabolism were exclusively anaerobic until the evolution of oxygen-producing
phototrophs
-life was exclusively microbial until ~1 billion years ago
Microbes Everywhere doing nearly Everything - Answer--Deinococcus can survive 3
million rads (3,00x radiation needed to kill a person)
-Halobacterium can live at 32% salinity (~9x sea water)
-Picrophilus lives at a pH of 0.003 (acidic enough to dissolve metals)
-Natranobacterium lives at a pH of 12
-Pyrolobus lives at temperatures >113°C
-Polaromonas lives at temperatures <0°C
-Moritella lives at pressure over 1,000 atms
Robert Hooke - Answer--while it had been suspected that there were organisms that
were too small to see, they were first discovered by Robert Hooke
-created the first microscope
, Louis Pasteur - Answer--discovered that alcoholic fermentation was a biologically
mediated process
-disproved theory of spontaneous generation which led to aseptic technique
-developed vaccines for anthrax, fowl cholera, and rabies
Robert Koch - Answer--demonstrated link between microbes and infectious diseases
-developed solid media techniques for obtaining pure cultures of microbes
-observed that masses of cells have different shapes, colors, and sizes
Great Plate Count Anomaly - Answer--difference between colony counts and counts
under a microscope
-viable but nonculturable populations: when a culture of cells is stressed, then it will no
longer grow in media
-uncultured populations: These could not be grown on typical media
Evolution - Answer--the process of change over time that results in new varieties and
species of organisms
-occurs in any self-replicating system in which variation occurs as the result of mutation
and selection and differential fitness is a potential result
-thus over time, all cells and viruses evolve
Phylogeny - Answer--evolutionary relationships between organisms
-relationships can be deduced by comparing genetic information in the different
specimens
-Ribosomal RNA (rRNA) is excellent for determining phylogeny
-all cells have rRNA
-they are rarely transferred between cells
-relationships visualized on a phylogenetic tree
-phylogenetic relationships between bacteria can be deduced by comparing genetic
information
Separating Microbes into Functional Groups - Answer--phototrophs obtain energy from
light
-chemotrophs obtain energy from chemicals
-autotrophs require CO2 as a carbon source
-heterotrophs require an organic nutrient to make organic compounds
Four major Modes of Nutrition - Answer--Photoautotrophy
-Chemoautotrophy
-Photoheterotrophy
-Chemoheterotrophy
Identifying Bacteria Based on Metabolic Capacity - Answer--did a swab and then did a
bunch of metabolic tests to determine if it was a certain organism
-not used in microbial ecology because it won't be able to tell you very much
