MICR 271 Module 1 Questions with Correct
Answers
What is the difference in between bacteria, archaea, and eukaryotes?
Bacteria: Single-celled organisms that can live freely or as a parasite.
Archaea: Single-celled organism without a membrane-bound nucleus or organelles.
Eukaryotes: Organism with nucleus and other membrane-bound organelles.
What is a microbe?
A microbe is a tiny organism that the naked eye cannot see. Microbes involve many
organisms, such as bacteria, viruses, protozoa, and other organisms. (a microscopic form of
life including bacterial, archaeal, fungal, and protozoal cells)
What does the endosymbiont hypothesis state? What is the supporting evidence?
The endosymbiont hypothesis states that eukaryotes evolved from prokaryotes. The
supporting evidence lies in the fact that mitochondria and chloroplasts have their own DNA
and replication systems, similarly to prokaryotes. A symbiotic relationship in between the
primitive archezoan cell and the alpha proteobacteria would have provided an advantage to
both.
What are the two mitochondrial symbiosis theories?
Archezoan scenario: Nucleus formation in a primitive archezoan occurs before the arrival of
the alpha proteobacteria. (Unlikely because studies of protists showed early integration of
mitochondria)
Endosymbiont scenario: Nucleus formation in the primitive archezoan occurred after the
integration of the alpha-proteobacteria into the archaeal ancestor.
What is phylogeny?
, Classification of species based on genetic similarities to determine evolutionary relationships.
What is a phylogenetic tree?
A picture of probable evolutionary relationships between species, based on measured
evidence in comparing rRNA sequences.
What are phylogenomics?
Comparison of entire genomes to determine evolutionary ties. This approach is much more
detailed than phylogenetics.
What is horizontal gene transfer?
Horizontal gene transfer is the passing of genetic material from on organism to the next in a
non-descendant nature.
Why do eukaryotes have more subunits in RNA polymerase?
More complex structures allow for a wider range of functions. This explains the complexity
of the organism.
Why is it important that only bacteria can produce murein?
Murein forms the cell wall (PG layer) which provides added protection and is solely found in
prokaryotes.
What is the importance of horizontal gene transfer in the tree of life?
The tree of life is more like a "web" of life due to the transfer of genetic material in between
the different evolutionary branches.
How is the tree of life divided in between the archaeans, the prokaryotes, and the
eukaryotes?
Answers
What is the difference in between bacteria, archaea, and eukaryotes?
Bacteria: Single-celled organisms that can live freely or as a parasite.
Archaea: Single-celled organism without a membrane-bound nucleus or organelles.
Eukaryotes: Organism with nucleus and other membrane-bound organelles.
What is a microbe?
A microbe is a tiny organism that the naked eye cannot see. Microbes involve many
organisms, such as bacteria, viruses, protozoa, and other organisms. (a microscopic form of
life including bacterial, archaeal, fungal, and protozoal cells)
What does the endosymbiont hypothesis state? What is the supporting evidence?
The endosymbiont hypothesis states that eukaryotes evolved from prokaryotes. The
supporting evidence lies in the fact that mitochondria and chloroplasts have their own DNA
and replication systems, similarly to prokaryotes. A symbiotic relationship in between the
primitive archezoan cell and the alpha proteobacteria would have provided an advantage to
both.
What are the two mitochondrial symbiosis theories?
Archezoan scenario: Nucleus formation in a primitive archezoan occurs before the arrival of
the alpha proteobacteria. (Unlikely because studies of protists showed early integration of
mitochondria)
Endosymbiont scenario: Nucleus formation in the primitive archezoan occurred after the
integration of the alpha-proteobacteria into the archaeal ancestor.
What is phylogeny?
, Classification of species based on genetic similarities to determine evolutionary relationships.
What is a phylogenetic tree?
A picture of probable evolutionary relationships between species, based on measured
evidence in comparing rRNA sequences.
What are phylogenomics?
Comparison of entire genomes to determine evolutionary ties. This approach is much more
detailed than phylogenetics.
What is horizontal gene transfer?
Horizontal gene transfer is the passing of genetic material from on organism to the next in a
non-descendant nature.
Why do eukaryotes have more subunits in RNA polymerase?
More complex structures allow for a wider range of functions. This explains the complexity
of the organism.
Why is it important that only bacteria can produce murein?
Murein forms the cell wall (PG layer) which provides added protection and is solely found in
prokaryotes.
What is the importance of horizontal gene transfer in the tree of life?
The tree of life is more like a "web" of life due to the transfer of genetic material in between
the different evolutionary branches.
How is the tree of life divided in between the archaeans, the prokaryotes, and the
eukaryotes?
