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25 Cards in this Set
- Front
- Back
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Which arose first; prokaryotic or eukaryotic cells? Why?
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Scientific evidence suggests that prokaryotes arose first. The name means "before the nucleus"; which eukaryotes posses.
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Describe the physical difference, from a morphological standpoint, between the DNA of prokaryotes and eukaryotes.
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Prokaryotic DNA tends to be circular in appearance. Eukaryotic DNA tends to be rod-like, or linear, in appearance.
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In what type of cells are plasmids found?
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Some prokaryotic cells possess plasmids - distinct circular pieces of DNA which is separate from the cellular DNA.
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What major cell organelle do prokaryotes lack?
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nucleus
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The vast majority of prokaryotic bacteria are pathogenic. True/False
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False. While their are many pathogenic bacteria to be sure, most live as important symbionts and are vital to global biological processes.
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What are the two Domains to which prokaryotic organisms belong?
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Archaea & Bacteria
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If one were to compare the global biomass of bacteria to eukaryotic cells, which would have the most?
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Global bacterial biomass outweighs eukaryotic biomass by a magnitude of 10 times, according to some recent estimates.
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Give one example of a common beneficial bacteria that is essential to plant life of Earth.
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nitrogen fixing bacteria
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Are Archaea more closely related to bacteria or to eukaryotes?
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Current evidence suggests that most Archaea are more closely related to eukaryotes than to bacteria.
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Name and spell correctly the singular form of four common bacteria shapes.
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round = coccus (pl. cocci)
rod-like = bacillus (pl. bacillus) spiral = spirillum (pl. spirilla) vibrio = vibrio (pl. Vibrio cholerae) both words underlined - cause of cholera |
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A common spirochete bacterium which causes syphilis, has what shape?
(Use the plural form) |
spirilla
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Which is physically larger, the typical prokaryotic cell, or the typical eukaryotic cell.
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Prokaryotic cells, on average, tend to be many magnitudes smaller than eukaryotic cells.
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Cells walls help to define the shape of bacterial cells. Are these walls found external or internal to the plasma membrane of the cell?
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external (outside the plasma membrane)
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Of what substance are most bacterial cell walls composed?
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peptidoglycan (as you can tell from the "roots" of the word - this cell wall is composed of a combination of protein and carbohydrates.
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Some types of bacteria have long whip-like structures extending from the outer membrane. What are these called?
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flagella
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During the gram staining process, which bacteria stain purple and why?
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gram positive - due to the uptake of crystal violet (purple) stain
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During the gram staining process, which bacteria stain red and why?
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gram negative bacteria - due to the uptake of safranin dye and the inability to the crystal violet stain to enter.
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Gram negative bacteria have a much more complex structure consisting of a cell wall with two membranes; the plasma membrane and the outer membrane. What is sandwiched between these two membranes?
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periplasmic gel composed of dense peptidoglycan
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What does the term "motile" mean?
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capable of movement
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In biology, what is the meaning of "taxis?"
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The responsive movement of a free-moving organism or cell toward or away from an external stimulus, such as light.
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What are bacteria called that move in a corkscrew-like fashion?
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spirochetes
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What is chemotaxis?
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The movement of an organism toward or away from a chemical.
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What is geotaxis?
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The movement of an organism in response to gravity.
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What is found in the nucleoid region of a prokaryote?
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DNA (This mass of DNA is usually one thousand times less than that found in eukaryotes.)
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What are the resistance bacterial structures called that can withstand unbelievably harsh conditions for very long periods?
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endospores - one type was revived in the lab that had been quiescent for 250,000,000 years.
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