MBIO 1010 Final Exam Questions With
Accurate Answers
What is microbiology? - ANSWER the study of organisms too small to see with
the naked eye: Bacteria, viruses, single celled eukaryotes
some microorganisms are visible to the naked eye: Fungi, algae
some microbes are multicellular Mycobacteria, slime molds
common characteristics of all cells - ANSWER - Cytoplasmic membrane:Barrier
that separates the inside of the cell from the outside environment
- Cytoplasm:Aqueous mixture of macromolecules, ions, and proteins
- Ribosomes: Site of protein synthesis
Four things you can expect to find in microbial cells - ANSWER - Genetic
material
All cells store their genetic information as DNA
The information is divided into functional units called genes
- Genome
A cells full compliment of genes
- Chromosome
A genetic element carrying genes essential to cellular function
- Plasmid
A piece of DNA that carries non-essential genes (ex: genes for antibiotic
resistance)
Luxury, not needed
Nothing stopping the cell from getting rid of info on the plasmid
Structures/division unique to eukaryotes - ANSWER Membrane bound nucleus
Membrane bound organelles
Complex internal organization
,Division by mitosis and meiosis
Eukaryotic Microbes: (2 groups) - ANSWER Protists: unicellular or multicellular
without differentiation into tissues
- protozoa: animal-like microorganisms
- algae: photosynthetic plant-like microorganisms
- slime molds and water molds — filamentous
Fungi: unicellular (yeasts)
- filamentous (molds) or
- multicellular (mushrooms)
Structures/division unique to Prokaryotes - ANSWER no membrane bound
nucleus or organelles
Generally smaller (approx 1 um diameter)
Simple internal structure
Divid by binary fission
Most are unicellular
Major groups of prokaryotic microbes (2 groups - ANSWER Bacteria:
(eubacteria)
genetically diverse
Extremely diverse metabolic styles
Includes both pathogenic and non-pathogens
Archaea: (archaebacteria)
genetically and biochemically distinct from bacteria
Also have diverse metabolism
Never pathogenic
Most famous for living in extreme environments
Exception to eukaryotic and prokaryotic microbes - ANSWER Viruses
acellular infectious particles
Extremely small
Obligate intracellular parasites
Lack independent metabolism
No ribosomes
,No ribosomal RNA
Cannot be classified with other microbes
first anaerobic life appeared: - ANSWER between 3.8 and 3.9 billion years ago
photosynthetic bacteria oxygenated the earth about: - ANSWER 2 billion years
ago
Allowed the evolution of modern eukaryotic organisms
First plants and animals appeared: - ANSWER about 0.5 billion years ago
Classifying organisms based on evolutionary relationships by comparing small
subunit rRNA genes
In prokaryotes - ANSWER using 70S ribosomes
16S Small SubUnit (SSU) rRNA
Classifying organisms based on evolutionary relationships by comparing small
subunit rRNA genes- in eukaryotes - ANSWER 80S ribosomes
18S Small SubUnit (SSU) rRNA
why do we use rRNA to track evolutionary differences - ANSWER rRNA changes
very slowly, and we can use it to examine genetic differences rather than
morphological differences
Basic steps involved in sequencing rRNA genes fro evolutionary purposes -
ANSWER Step 1: DNA is collected from a pure culture
Step 2: the SSU rRNA gene is amplified using the polymerase chain reaching
(PCR)
- PCR — a technique used to synthesize many identical copies of a short
sequence of DNA
Step 3: the gene is sequenced
Step 4: sequence is aligned with sequences form other organisms
- the number of differences is used to calculate evolutionary distance
Phylogenic tree - ANSWER a graphic representation of the evolutionary distance
between organisms.
Molecular phylogeny and the tree of life
, based on 16S or 18S ribosomal DNA sequences
All organisms can be grouped into 3 distinct domains of life: - ANSWER bacteria,
archaea, and eukarya
which are more diverse: microorganisms or plants/animals? - ANSWER
microorganisms
what is a species? - ANSWER A group of strains that share certain diagnostic
traits, are genetically cohesive and have a unique recent common ancestor
Species concept in microbiology: species of bacteria and archaea should have: -
ANSWER - Most (but not all) characteristics in common
- Greater than 97% sequence similarity in the 16S rRNA gene, 96% specificity
would not be considered the same species.
-High degree of genome similarity
Binomial species name - ANSWER - genus first (Capitalized)
- Specific epithet/species (not capitalized)
- Names are latinized
Italicized or underlined
- Genus name may be abbreviated the second time it's used
- Trivial names can be used, but do not follow these rules
- Strains can be identified by symbols after the species name, for example: E.
coli K12
Robert hooke: (1635-1703) - ANSWER First to describe microbes
used a compound microscope — use 2 lenses to magnify the image
Allowed magnification up to 30x
Used it to observe Cells in cork Bread mold filaments — 1st microbe
Beginning of cell theory: — all living things are composed of cells
Antoni van Leeuwenhoek (1632-1723) - ANSWER Built microscopes that
magnified specimen. By 50-300x
Observed single cell microorganisms — called them "animalcules"
First discovery of bacteria
Louis Pasteur: 1822-1895 - ANSWER studied wine and beer production
Accurate Answers
What is microbiology? - ANSWER the study of organisms too small to see with
the naked eye: Bacteria, viruses, single celled eukaryotes
some microorganisms are visible to the naked eye: Fungi, algae
some microbes are multicellular Mycobacteria, slime molds
common characteristics of all cells - ANSWER - Cytoplasmic membrane:Barrier
that separates the inside of the cell from the outside environment
- Cytoplasm:Aqueous mixture of macromolecules, ions, and proteins
- Ribosomes: Site of protein synthesis
Four things you can expect to find in microbial cells - ANSWER - Genetic
material
All cells store their genetic information as DNA
The information is divided into functional units called genes
- Genome
A cells full compliment of genes
- Chromosome
A genetic element carrying genes essential to cellular function
- Plasmid
A piece of DNA that carries non-essential genes (ex: genes for antibiotic
resistance)
Luxury, not needed
Nothing stopping the cell from getting rid of info on the plasmid
Structures/division unique to eukaryotes - ANSWER Membrane bound nucleus
Membrane bound organelles
Complex internal organization
,Division by mitosis and meiosis
Eukaryotic Microbes: (2 groups) - ANSWER Protists: unicellular or multicellular
without differentiation into tissues
- protozoa: animal-like microorganisms
- algae: photosynthetic plant-like microorganisms
- slime molds and water molds — filamentous
Fungi: unicellular (yeasts)
- filamentous (molds) or
- multicellular (mushrooms)
Structures/division unique to Prokaryotes - ANSWER no membrane bound
nucleus or organelles
Generally smaller (approx 1 um diameter)
Simple internal structure
Divid by binary fission
Most are unicellular
Major groups of prokaryotic microbes (2 groups - ANSWER Bacteria:
(eubacteria)
genetically diverse
Extremely diverse metabolic styles
Includes both pathogenic and non-pathogens
Archaea: (archaebacteria)
genetically and biochemically distinct from bacteria
Also have diverse metabolism
Never pathogenic
Most famous for living in extreme environments
Exception to eukaryotic and prokaryotic microbes - ANSWER Viruses
acellular infectious particles
Extremely small
Obligate intracellular parasites
Lack independent metabolism
No ribosomes
,No ribosomal RNA
Cannot be classified with other microbes
first anaerobic life appeared: - ANSWER between 3.8 and 3.9 billion years ago
photosynthetic bacteria oxygenated the earth about: - ANSWER 2 billion years
ago
Allowed the evolution of modern eukaryotic organisms
First plants and animals appeared: - ANSWER about 0.5 billion years ago
Classifying organisms based on evolutionary relationships by comparing small
subunit rRNA genes
In prokaryotes - ANSWER using 70S ribosomes
16S Small SubUnit (SSU) rRNA
Classifying organisms based on evolutionary relationships by comparing small
subunit rRNA genes- in eukaryotes - ANSWER 80S ribosomes
18S Small SubUnit (SSU) rRNA
why do we use rRNA to track evolutionary differences - ANSWER rRNA changes
very slowly, and we can use it to examine genetic differences rather than
morphological differences
Basic steps involved in sequencing rRNA genes fro evolutionary purposes -
ANSWER Step 1: DNA is collected from a pure culture
Step 2: the SSU rRNA gene is amplified using the polymerase chain reaching
(PCR)
- PCR — a technique used to synthesize many identical copies of a short
sequence of DNA
Step 3: the gene is sequenced
Step 4: sequence is aligned with sequences form other organisms
- the number of differences is used to calculate evolutionary distance
Phylogenic tree - ANSWER a graphic representation of the evolutionary distance
between organisms.
Molecular phylogeny and the tree of life
, based on 16S or 18S ribosomal DNA sequences
All organisms can be grouped into 3 distinct domains of life: - ANSWER bacteria,
archaea, and eukarya
which are more diverse: microorganisms or plants/animals? - ANSWER
microorganisms
what is a species? - ANSWER A group of strains that share certain diagnostic
traits, are genetically cohesive and have a unique recent common ancestor
Species concept in microbiology: species of bacteria and archaea should have: -
ANSWER - Most (but not all) characteristics in common
- Greater than 97% sequence similarity in the 16S rRNA gene, 96% specificity
would not be considered the same species.
-High degree of genome similarity
Binomial species name - ANSWER - genus first (Capitalized)
- Specific epithet/species (not capitalized)
- Names are latinized
Italicized or underlined
- Genus name may be abbreviated the second time it's used
- Trivial names can be used, but do not follow these rules
- Strains can be identified by symbols after the species name, for example: E.
coli K12
Robert hooke: (1635-1703) - ANSWER First to describe microbes
used a compound microscope — use 2 lenses to magnify the image
Allowed magnification up to 30x
Used it to observe Cells in cork Bread mold filaments — 1st microbe
Beginning of cell theory: — all living things are composed of cells
Antoni van Leeuwenhoek (1632-1723) - ANSWER Built microscopes that
magnified specimen. By 50-300x
Observed single cell microorganisms — called them "animalcules"
First discovery of bacteria
Louis Pasteur: 1822-1895 - ANSWER studied wine and beer production
