Test 1 Study questions Flashcards
(49 cards)
______ membranes allow some molecules to pass but not others
Selectively permeable
What occurs when motile bacteria is placed in an environment with a gradient of a chemical attractant? What behavior would be predicted?
The bacteria will both reduce tumbling frequency and increase run duration in the direction of the chemical
Flexible bacteria with a helical shape are called
spirochetes
What does the cytoplasmic membrane of bacteria do?
- It retains the cytoplasm and its contents
- It acts a selectively permeable barrier, allowing some molecules to pass while preventing the movement of others
- It is the major site of ATP synthesis in aerobes
Chemotaxis is a process by which bacteria do what?
Move toward an attractant or away from a repellent
Which of the following is not considered a macronutrient?
Cobalt
What would happen to the surface area and volume of a spherical cell if the diameter of the cell doubles?
The surface area will increase by a factor of 4, while the volume will increase by a factor of 8
How exactly is the assembly of the flagellar filament?
The flagellin protein monomers assemble from the base of the flagellum within the cell envelope
Are all vesicles produced by the same mechanism of transporting material between cells?
They are not produced by the same mechanism
Organisms that ignore oxygen and grow equally well in its presence or absence are called
Aerotolerant
For surface cultivation of microorganisms, a sulfated polymer called agar can be extracted from ____ and added to liquid media in order to cause it to solidify
algae
Which of the following are reasons for the decline in a cell numbers during the death phase?
- Depletion of nutrients
- Accumulation of toxic waste materials
3.Depletion of O2
Which of the following can be used to isolate pure cultures of bacteria from mixtures?
- Spread plates
- Streak plates
- Pour plates
A cell may enter a stationary phrase because of
- the depletion of an essential nutrient
- a lack of available oxygen
- the accumulation of toxic waste products
The growth rate of a given specifies of micoorganism is dependent on?
The composition of the medium in which it is grown
Obligate anaerobes are usually poisoned by molecular oxygen but may grown in aerobic habitats if associated with facultative anaerobes that use up all available oxygen
This is true
Most microorganism do not?
live in eutrophic environments
Is it true that the size and shape of a colony is not useful for identification of microorganisms because microorganisms produce colonies that are indistinguishable from one another?
That is false they can be useful for identification
What does binary fission do?
Divides one cell into two identical daughter cells
Who suggested that disease was caused by invisible living creatures?
Roman Philosopher Lucretius and Physician Girolamo Fracastoro
How would one define microbiology?
It would be defined by not only the organisms it studies but also the tools used to study them
What is the role of microbes in maintaining temperature on earth?
They convert CO2 to CH4 (methane) both are which are green house gases that regulate temperature
List the top three causes of death in the U.S.
Heart diseases, cancer, stroke
How did the role of microbes change over the last 100 years?
1.Over the last 100 years there has been the clean water act (H2O purification and sewage treatment)
2. Vaccine
3. Antibiotics (Alexander Fleming)