BIO 351 EXAM 1 REVIEW QUESTIONS AND
ANSWERS
What are the relationships between a millimetre, a micrometre, a nanometer,
and an angstrom? - ANSWER 1mm = 1000um = 1,000,000nm = 10,000,000 A
The fossil record indicates that cyanobacteria were present about 3 billion years
ago. Cyanobacteria are photosynthetic bacteria that produce O2 as a byproduct
of photosynthesis. Approximately when did the Earth develop an oxygen
atmosphere? - ANSWER Approx. 2.7 BYA
Which would be most alike, two organisms in the same family or two organisms
in the same genus? - ANSWER 2 organisms from the same genus would be
more alike than 2 from the same family
Explain the difference between phenotypic and phylogenetic classification. -
ANSWER Phenotypic classification does not have a true genetic basis as it is
based upon phenotypes which can be plastic whereas phylogenetic is a
molecular based approach to organizing different clades.
What are the reasons why the genes encoding the small ribosomal subunit RNA
are used for doing phylogenetic comparisons? - ANSWER The rRNA gene is
highly conserved between different species of bacteria and archaea, but still has
characteristic differences
What is a small subunit rRNA signature sequence? - ANSWER 16S rRNA
, What feature of the cell wall distinguishes most Bacteria from all known
Archaea and Eukaryotes? - ANSWER Bacterial cell walls contain murein w/
muramic acid
What feature(s) of membrane structure is shared by Bacteria and Eukaryotes? -
ANSWER Bacterial and Eukaryotic membrane lipids are ester-linked straight
chain fatty acids
What feature(s) of membrane structure are unique to the Archaea? - ANSWER
Archaea membranes are ether-linked, and they have branched aliphatic chains
One function of the plasma membrane is to provide a selectively-permeable
barrier between the cytoplasm and the environment. What other cellular
functions are associated with the plasma membrane? - ANSWER Holding cell
contents together, encompass the cytoplasm, location of important metabolic
processes, detection of and response to molecules in the environment.
What type of molecules can diffuse across the plasma membrane without the aid
of transport proteins? - ANSWER gases, hydrophobic molecules, small polar
but uncharged molecules
Describe the structure of the phospholipids that are found in the plasma
membranes of bacterial and eukaryotic cells. - ANSWER Phosphate,
hydrophilic head on outside of bilayer, w/hydrocarbon hydrophobic tail facing
inward of the bilayer, archaea have tetra ethers that are basically connected
bilayers
What kinds of molecules do bacteria use in place of sterols in their membranes,
and what is the functional consequence of incorporating such molecules into
membranes? ANSWER Bacteria contain hopanoids whereas euks contain
cholesterol these keep membranes fluid
ANSWERS
What are the relationships between a millimetre, a micrometre, a nanometer,
and an angstrom? - ANSWER 1mm = 1000um = 1,000,000nm = 10,000,000 A
The fossil record indicates that cyanobacteria were present about 3 billion years
ago. Cyanobacteria are photosynthetic bacteria that produce O2 as a byproduct
of photosynthesis. Approximately when did the Earth develop an oxygen
atmosphere? - ANSWER Approx. 2.7 BYA
Which would be most alike, two organisms in the same family or two organisms
in the same genus? - ANSWER 2 organisms from the same genus would be
more alike than 2 from the same family
Explain the difference between phenotypic and phylogenetic classification. -
ANSWER Phenotypic classification does not have a true genetic basis as it is
based upon phenotypes which can be plastic whereas phylogenetic is a
molecular based approach to organizing different clades.
What are the reasons why the genes encoding the small ribosomal subunit RNA
are used for doing phylogenetic comparisons? - ANSWER The rRNA gene is
highly conserved between different species of bacteria and archaea, but still has
characteristic differences
What is a small subunit rRNA signature sequence? - ANSWER 16S rRNA
, What feature of the cell wall distinguishes most Bacteria from all known
Archaea and Eukaryotes? - ANSWER Bacterial cell walls contain murein w/
muramic acid
What feature(s) of membrane structure is shared by Bacteria and Eukaryotes? -
ANSWER Bacterial and Eukaryotic membrane lipids are ester-linked straight
chain fatty acids
What feature(s) of membrane structure are unique to the Archaea? - ANSWER
Archaea membranes are ether-linked, and they have branched aliphatic chains
One function of the plasma membrane is to provide a selectively-permeable
barrier between the cytoplasm and the environment. What other cellular
functions are associated with the plasma membrane? - ANSWER Holding cell
contents together, encompass the cytoplasm, location of important metabolic
processes, detection of and response to molecules in the environment.
What type of molecules can diffuse across the plasma membrane without the aid
of transport proteins? - ANSWER gases, hydrophobic molecules, small polar
but uncharged molecules
Describe the structure of the phospholipids that are found in the plasma
membranes of bacterial and eukaryotic cells. - ANSWER Phosphate,
hydrophilic head on outside of bilayer, w/hydrocarbon hydrophobic tail facing
inward of the bilayer, archaea have tetra ethers that are basically connected
bilayers
What kinds of molecules do bacteria use in place of sterols in their membranes,
and what is the functional consequence of incorporating such molecules into
membranes? ANSWER Bacteria contain hopanoids whereas euks contain
cholesterol these keep membranes fluid
