MICR 271 - MODULE 1 EXAM 2025
QUESTIONS AND ANSWERS
What is the difference in between bacteria, archaea, and eukaryotes? - ANS 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? - ANS 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? - ANS 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.
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, What are the two mitochondrial symbiosis theories? - ANS 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? - ANS Classification of species based on genetic similarities to determine
evolutionary relationships.
What is a phylogenetic tree? - ANS A picture of probable evolutionary relationships between
species, based on measured evidence in comparing rRNA sequences.
What are phylogenomics? - ANS Comparison of entire genomes to determine evolutionary
ties. This approach is much more detailed than phylogenetics.
What is horizontal gene transfer? - ANS Horizontal gene transfer is the passing of genetic
material from on organism to the next in a non-descendant nature.
2 Copyright ©2025 FYNDLAY ALL RIGHTS RESERVED.
QUESTIONS AND ANSWERS
What is the difference in between bacteria, archaea, and eukaryotes? - ANS 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? - ANS 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? - ANS 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.
1 Copyright ©2025 FYNDLAY ALL RIGHTS RESERVED.
, What are the two mitochondrial symbiosis theories? - ANS 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? - ANS Classification of species based on genetic similarities to determine
evolutionary relationships.
What is a phylogenetic tree? - ANS A picture of probable evolutionary relationships between
species, based on measured evidence in comparing rRNA sequences.
What are phylogenomics? - ANS Comparison of entire genomes to determine evolutionary
ties. This approach is much more detailed than phylogenetics.
What is horizontal gene transfer? - ANS Horizontal gene transfer is the passing of genetic
material from on organism to the next in a non-descendant nature.
2 Copyright ©2025 FYNDLAY ALL RIGHTS RESERVED.
