Microbiology Ch 4 Hwrk Quiz
The bacterial flagellum moves
by rotation that is powered by the proton motive force
Excess nutrients that the cell may store for later may be found within
cytoplasmic granules
Which of the following has historically been the first division in a system of bacterial taxonomy?
Gram-positive vs gram-negative cells
A taxonomical outline of bacterial species based on shared evolutionary histories would be described as
Phylogenic system
The best understood bacterial cytoskeletons are composed primarily of
actin
The two groups of obligate intracellular bacteria are the ______, usually spread by contact, and the _____, usually transmitted by the bites of arthropods.
Chlamydias; ricketssias
Which of the following explains why archaeons are extremophiles?
They are ancient, primitive organisms that adapt well to extreme conditions because they have retained characteristics of the cells that first evolved when earth's conditions were far more extreme
Other than maintaining the shape of the cell, what is the primary function of the cell wall, and which component contributes most to this function?
maintaining strength; peptidoglycan
Bacterial species are defined in a fundamentally different way than the mammalian species are. This is because
mammals reproduce sexually while bacteria reproduce asexually
Of the photosynthetic bacteria, cyanobacteria produce _____ as a product of photosynthesis but the green and purple sulfur bacteria do not produce this substance
oxygen
The molecule primarily responsible for the strength and stability of the bacterial cell wall is
peptidoglycan
The cell membrane is composed of
proteins dispersed throughout a phospholipid bilayer
Choose the answer that best completes this statement's blanks in the correct order. When all the flagella on a cell rotate in a counterclockwise fashion, the cell is propelled forward in a movement known as a _____, but when the flagella reverse direction, the cell stops and changes course in an action known as a _____.
run; tumble
The primary function of the cell membrane is
to regulate the transport of molecules in and out of the cell
The ____ level of bacterial organisms refers to a group of organisms that all share the same traits while the subspecies level refers to the variation or differences of individual cells within that group.
species
Ribosomes function primarily to
synthesize proteins