CAMPBELL BIOLOGY CHAPTER 27
QUESTIONS AND ANSWERS
peptidoglycan - answer- A protein-carbohydrate compound that makes the cell walls
of bacteria rigid
gram stain - answer- A staining method that distinguishes between two different
kinds of bacterial cell walls.
gram positive - answer- Describing the group of bacteria that have a cell wall that is
structurally less complex and contains more peptidoglycan than the cell wall of gram-
negative bacteria. Gram-positive bacteria are usually less toxic than gram-negative
bacteria.
gram negative - answer- Describing the group of bacteria that have a cell wall that is
structurally more complex and contains less peptidoglycan than the cell wall of gram-
positive bacteria. Gram-negative bacteria are often more toxic than gram-positive
bacteria.
flagellum - answer- a long, hairlike structure that grows out of a cell and enables the
cell to move
plasmids - answer- The smalll, circular segments of DNA that are found in bacteria
and that stay sparate from the bacterial chromosomes; used in genetic engineering.
endospores - answer- A thick-walled protective spore that forms inside a bacterial
cell and resists harsh conditions
transformation - answer- modification of a cell or bacterium by the uptake and
incorporation of exogenous DNA
transduction - answer- the process of transfering genetic material from one cell to
another by a plasmid or bacteriophage
conjugation - answer- form of sexual reproduction in which paramecia and some
prokaryotes exchange genetic information
Obligate aerobes - answer- organisms that require a constant supply of oxygen in
order to live
Obligate anaerobes - answer- organisms that cannot live where molecular oxygen is
present
anaerobic respiration - answer- Respiration that does not require oxygen
nitrogen fixation - answer- the assimilation of atmospheric nitrogen by soil bacteria
and its release for plant use on the death of the bacteria
QUESTIONS AND ANSWERS
peptidoglycan - answer- A protein-carbohydrate compound that makes the cell walls
of bacteria rigid
gram stain - answer- A staining method that distinguishes between two different
kinds of bacterial cell walls.
gram positive - answer- Describing the group of bacteria that have a cell wall that is
structurally less complex and contains more peptidoglycan than the cell wall of gram-
negative bacteria. Gram-positive bacteria are usually less toxic than gram-negative
bacteria.
gram negative - answer- Describing the group of bacteria that have a cell wall that is
structurally more complex and contains less peptidoglycan than the cell wall of gram-
positive bacteria. Gram-negative bacteria are often more toxic than gram-positive
bacteria.
flagellum - answer- a long, hairlike structure that grows out of a cell and enables the
cell to move
plasmids - answer- The smalll, circular segments of DNA that are found in bacteria
and that stay sparate from the bacterial chromosomes; used in genetic engineering.
endospores - answer- A thick-walled protective spore that forms inside a bacterial
cell and resists harsh conditions
transformation - answer- modification of a cell or bacterium by the uptake and
incorporation of exogenous DNA
transduction - answer- the process of transfering genetic material from one cell to
another by a plasmid or bacteriophage
conjugation - answer- form of sexual reproduction in which paramecia and some
prokaryotes exchange genetic information
Obligate aerobes - answer- organisms that require a constant supply of oxygen in
order to live
Obligate anaerobes - answer- organisms that cannot live where molecular oxygen is
present
anaerobic respiration - answer- Respiration that does not require oxygen
nitrogen fixation - answer- the assimilation of atmospheric nitrogen by soil bacteria
and its release for plant use on the death of the bacteria
