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Chapter 11 Micro Questions and Answers (100%
Correct Answers)
Identify six basic shapes of prokaryotic cells.
Ans: Coccus, bacillus, spiral, spirochetes/spirilla, vibrios, and coccobacillus.
Coccus
Ans: Roughly spherical
Bacillus
Ans: Rod-shaped
Spiral-shaped prokaryotes are either two types...
Ans: Spirilla, which are stiff, or spirochetes which are flexible.
Vibrios
Ans: Curved rods
Coccobacillus
Ans: Used to describe cells that are intermediate in shape between cocci and bacilli;
that is, it is difficult to ascertain if a Coccobacillus is an elongated coccus or short
bacillus.
Pleomorphic
Ans: Prokaryotic cells that vary in shape and size.
Why are endospores important?
Ans: Their durability and potential pathogenicity; They constitute a defensive
strategy against hostile or unfavorable conditions. They are stable resting stages that
barely metabolize and germinate when conditions improve.
What produces endospores?
Ans: The Gram-positive bacteria Bacillus and Clostridium.
Sporulation
Ans: The process of endospore formation, requires 8-10 hours and proceeds in
seven steps. Depending on the species, a vegetative cell forms an endospore either
centrally, subterminally (near one end), or terminally (at one end).
Why are food processors, health care professionals, and governments concerned
about endospore formation?
Ans: Endospores can resist our attempts to kill them and because many endospore-
forming bacteria produce deadly toxins that cause fatal diseases, such as anthrax,
tetanus, and gangrene.
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List three common types of reproduction in prokaryotes.
Ans: Binary fission, spore formation, and budding.
Binary Fission
Ans: The most common method of asexual reproduction of prokaryotes, in which
the parental cell disappears with the formation of progeny.
Budding
Ans: In prokaryotes and yeasts, reproductive process in which an outgrowth of the
parent cell receives a copy of the genetic material, enlarges, and detaches.
Snapping division
Ans: A variation of binary fission; Occurs in some Gram-positive bacilli. Only the
inner portion of a cell wall is deposited across the dividing cell. As the cells grow and
the new cross wall thickens, they put tension on the outer layer of the old cell wall,
which still holds the two cells together. Eventually, as the tension increases, the
outer wall breaks at its weakest point with a snapping movement that tears it most of
the way around. The daughter cells then remain hanging together almost side by
side, held at an angle by a small remnant of the original outer wall that acts like a
hinge.
Viviparity
Ans: Epulopiscium, a giant bacterium that lives inside surgeonfish, and many of its
relatives have a truly unique method of reproduction among prokaryotes: They give
"birth" to as many as 12 live offspring that emerge from the body of their dead
mother cell; The production of live offspring within a mother.
What are nine arrangements of prokaryotes?
Ans: Diplococci, streptococci, tetrads, sarcinae, staphylococci, single bacillus,
diplobacilli, streptobacilli, palisade and v-shape.
Diplococci
Ans: Cocci that remain attached in pairs.
Streptococci
Ans: Long chains of cocci.
Tetrads
Ans: Cocci divide in two planes and remain attached.
Sarcinae
Ans: Cocci divide in three planes to form cuboidal packets.
Staphylococci
Ans: Clusters; look like bunches of grapes, form when the planes of cell division are
random.
Chapter 11 Micro Questions and Answers (100%
Correct Answers)
Identify six basic shapes of prokaryotic cells.
Ans: Coccus, bacillus, spiral, spirochetes/spirilla, vibrios, and coccobacillus.
Coccus
Ans: Roughly spherical
Bacillus
Ans: Rod-shaped
Spiral-shaped prokaryotes are either two types...
Ans: Spirilla, which are stiff, or spirochetes which are flexible.
Vibrios
Ans: Curved rods
Coccobacillus
Ans: Used to describe cells that are intermediate in shape between cocci and bacilli;
that is, it is difficult to ascertain if a Coccobacillus is an elongated coccus or short
bacillus.
Pleomorphic
Ans: Prokaryotic cells that vary in shape and size.
Why are endospores important?
Ans: Their durability and potential pathogenicity; They constitute a defensive
strategy against hostile or unfavorable conditions. They are stable resting stages that
barely metabolize and germinate when conditions improve.
What produces endospores?
Ans: The Gram-positive bacteria Bacillus and Clostridium.
Sporulation
Ans: The process of endospore formation, requires 8-10 hours and proceeds in
seven steps. Depending on the species, a vegetative cell forms an endospore either
centrally, subterminally (near one end), or terminally (at one end).
Why are food processors, health care professionals, and governments concerned
about endospore formation?
Ans: Endospores can resist our attempts to kill them and because many endospore-
forming bacteria produce deadly toxins that cause fatal diseases, such as anthrax,
tetanus, and gangrene.
, 2 Inquire through: | Professional | Confidential Support
List three common types of reproduction in prokaryotes.
Ans: Binary fission, spore formation, and budding.
Binary Fission
Ans: The most common method of asexual reproduction of prokaryotes, in which
the parental cell disappears with the formation of progeny.
Budding
Ans: In prokaryotes and yeasts, reproductive process in which an outgrowth of the
parent cell receives a copy of the genetic material, enlarges, and detaches.
Snapping division
Ans: A variation of binary fission; Occurs in some Gram-positive bacilli. Only the
inner portion of a cell wall is deposited across the dividing cell. As the cells grow and
the new cross wall thickens, they put tension on the outer layer of the old cell wall,
which still holds the two cells together. Eventually, as the tension increases, the
outer wall breaks at its weakest point with a snapping movement that tears it most of
the way around. The daughter cells then remain hanging together almost side by
side, held at an angle by a small remnant of the original outer wall that acts like a
hinge.
Viviparity
Ans: Epulopiscium, a giant bacterium that lives inside surgeonfish, and many of its
relatives have a truly unique method of reproduction among prokaryotes: They give
"birth" to as many as 12 live offspring that emerge from the body of their dead
mother cell; The production of live offspring within a mother.
What are nine arrangements of prokaryotes?
Ans: Diplococci, streptococci, tetrads, sarcinae, staphylococci, single bacillus,
diplobacilli, streptobacilli, palisade and v-shape.
Diplococci
Ans: Cocci that remain attached in pairs.
Streptococci
Ans: Long chains of cocci.
Tetrads
Ans: Cocci divide in two planes and remain attached.
Sarcinae
Ans: Cocci divide in three planes to form cuboidal packets.
Staphylococci
Ans: Clusters; look like bunches of grapes, form when the planes of cell division are
random.
