MICR 271 - Module 1 Exam Questions And
Complete Answers
What is the difference in between bacteria, archaea, and eukaryotes? - answer 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? - answer 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? - answer
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? - answer 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? - answer Classification of species based on genetic similarities to
determine evolutionary relationships.
What is a phylogenetic tree? - answer A picture of probable evolutionary relationships
between species, based on measured evidence in comparing rRNA sequences.
What are phylogenomics? - answer Comparison of entire genomes to determine
evolutionary ties. This approach is much more detailed than phylogenetics.
What is horizontal gene transfer? - answer Horizontal gene transfer is the passing of
