MBIO 3401 Exam 3 QUESTION AND ANSWERS WITH ACTUAL
CORRECT DETAILED ANSWERS
What are the fundamental conditions require to sustain life? - ANSWER-1.essential elements
2.continual source of energy (sun)
3.temperature range permitting liquid water
What is another name for "evidence of early life?" - ANSWER-biosignature
what are three biosignatures - ANSWER-1. isotope ratios
2. stromatolites
3. microfossils
What are the models for the first cells? - ANSWER-1. prebiotic soup
2. early oxidation-reduction reactions
3. RNA world
What is a stromatolite? - ANSWER-layers deposits (cyanobacteria) formed by the growth of
blue-green algae
What is prebiotic soup? - ANSWER-blend of gases forming a broth when exposed to light or
head then forming the building blocks of life
,How did organisms diverge from each other? - ANSWER-1. random mutations
2. natural selection
3. reductive (degenerative) evolution
What is a molecular clock? - ANSWER-method used by researchers that uses mutation rates in
DNA to estimate the length of time that two species have been evolving independently
what is the most widely used molecular clock? - ANSWER-The gene encoding the small subunit
rRNA (SSU rRNA)
what does DNA sequence alignment compare? - ANSWER-the similarity and identity of amino
acids and DNA
what are the three domains of life? - ANSWER-Bacteria, Archaea, Eukarya
What is the criteria for a working definition of a species - ANSWER-1. SSU rRNA greater/equal to
95%
2. avg. nucleotide identity of ortholog genes greater/equal to 95%
3. shared ecotype between organisms greater/equal to 95%
What is vertical gene transfer? - ANSWER-transmission of genes from parent to offspring
What is horizontal gene transfer? - ANSWER-acquisition of genes from another organism in the
same generation
What is symbiosis? - ANSWER-the intimate association of two species
, What is mutualism? - ANSWER-both organisms benefit
What is parasitism? - ANSWER-One organism benefits and the other is harmed
When does endosymbiosis occur? - ANSWER-when one partner grows within the body of
another
Streptomyces - ANSWER--linear chromosome with telomeres
-major antibiotic producer
-looks like mold but is bacteria
what is an example of actinomycetes? - ANSWER-streptomycin
Mycobacterium - ANSWER--thick cell walls containing mycolic acids (mycomembrane)
-appears gram-negative because of tightly packed mycolic acid cell wall
what are some examples of mycobacterium - ANSWER-M. Tuberculosis, M. Leprae
What are the gram positive bacteria? - ANSWER-Actinomycetes and Nonmycelial actinobacteria
Proteobacteria - ANSWER--triple layered cell envelope
-DIVERSE METABOLISM
what is photoheterotropy? - ANSWER-able to switch metabolic pathways
CORRECT DETAILED ANSWERS
What are the fundamental conditions require to sustain life? - ANSWER-1.essential elements
2.continual source of energy (sun)
3.temperature range permitting liquid water
What is another name for "evidence of early life?" - ANSWER-biosignature
what are three biosignatures - ANSWER-1. isotope ratios
2. stromatolites
3. microfossils
What are the models for the first cells? - ANSWER-1. prebiotic soup
2. early oxidation-reduction reactions
3. RNA world
What is a stromatolite? - ANSWER-layers deposits (cyanobacteria) formed by the growth of
blue-green algae
What is prebiotic soup? - ANSWER-blend of gases forming a broth when exposed to light or
head then forming the building blocks of life
,How did organisms diverge from each other? - ANSWER-1. random mutations
2. natural selection
3. reductive (degenerative) evolution
What is a molecular clock? - ANSWER-method used by researchers that uses mutation rates in
DNA to estimate the length of time that two species have been evolving independently
what is the most widely used molecular clock? - ANSWER-The gene encoding the small subunit
rRNA (SSU rRNA)
what does DNA sequence alignment compare? - ANSWER-the similarity and identity of amino
acids and DNA
what are the three domains of life? - ANSWER-Bacteria, Archaea, Eukarya
What is the criteria for a working definition of a species - ANSWER-1. SSU rRNA greater/equal to
95%
2. avg. nucleotide identity of ortholog genes greater/equal to 95%
3. shared ecotype between organisms greater/equal to 95%
What is vertical gene transfer? - ANSWER-transmission of genes from parent to offspring
What is horizontal gene transfer? - ANSWER-acquisition of genes from another organism in the
same generation
What is symbiosis? - ANSWER-the intimate association of two species
, What is mutualism? - ANSWER-both organisms benefit
What is parasitism? - ANSWER-One organism benefits and the other is harmed
When does endosymbiosis occur? - ANSWER-when one partner grows within the body of
another
Streptomyces - ANSWER--linear chromosome with telomeres
-major antibiotic producer
-looks like mold but is bacteria
what is an example of actinomycetes? - ANSWER-streptomycin
Mycobacterium - ANSWER--thick cell walls containing mycolic acids (mycomembrane)
-appears gram-negative because of tightly packed mycolic acid cell wall
what are some examples of mycobacterium - ANSWER-M. Tuberculosis, M. Leprae
What are the gram positive bacteria? - ANSWER-Actinomycetes and Nonmycelial actinobacteria
Proteobacteria - ANSWER--triple layered cell envelope
-DIVERSE METABOLISM
what is photoheterotropy? - ANSWER-able to switch metabolic pathways
