What is the function of glycocalyces and fimbriae in forming a biofilm?

Which of the following statements concerning growth and reproduction is false?

a. Growth and reproduction may occur simultaneously in living organisms.

b. A living organism must reproduce to be considered alive.

c. Living things may stop growing and reproducing yet still be alive.

d. Normally, living organisms have the ability to grow and reproduce themselves.

What is the difference between growth and reproduction?

Facultative anaerobes can live under either aerobic or anaerobic conditions. What metabolic pathways allow these organisms to continue to harvest energy from sugar molecules in the absence of oxygen?

In a defined medium, ________.

a. the exact chemical composition of the medium is known

b. agar is available for microbial nutrition

c. blood may be included

d. organic chemicals are excluded

Label each of these thioglycolate tubes to indicate the oxygen requirements of the microbes growing in them.

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A student observes a researcher streaking a plate numerous times, flaming the loop between streaks. The researcher is likely using the ___________ method to isolate microorganisms.

List five direct methods of counting microbes.

High temperature affects the shape of particular molecules. How does this affect the life of a microbe?

Which of the following is most useful in representing population growth on a graph?

a. logarithmic reproduction of the growth curve

b. a semilogarithmic graph using a log scale on the y-axis

c. an arithmetic graph of the lag phase followed by a logarithmic section for the log, stationary, and death phases

d. None of the above would best represent a population growth curve.

Which of the following methods is best for counting fecal bacteria from a stream to determine the safety of the water for drinking?

a. dry weight

b. turbidity

c. viable plate counts

d. membrane filtration

A Coulter counter is a(n)_______.

a. statistical estimation using 15 dilution tubes and a table of numbers to estimate the number of bacteria per milliliter

b. indirect method of counting microorganisms

c. device that directly counts microbes as they pass through a tube in front of an electronic detector

d. device that directly counts microbes that are differentially stained with fluorescent dyes

Quorum sensing is _______.

a. the ability to respond to changes in population density

b. a characteristic allowing secretion of a matrix

c. dependent on direct contact among cells

d. associated with colonies in broth culture

“In the laboratory, a sterile inoculating loop is moved across the agar surface in a culture dish, thinning a sample and isolating individuals.” This statement describes which of the following?

a. broth culture

b. pour plate

c. streak plate

d. dilution plate

Support or refute the following statement: Microbes cannot tolerate the low pH of the human stomach.

Describe the type of hemolysis shown by the pathogen Staphylococcus aureus pictured here.

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Superoxide dismutase _________.

a. causes hydrogen peroxide to become toxic

b. detoxifies superoxide radicals

c. neutralizes singlet oxygen

d. is missing in aerobes

All cells recycle the essential element ___________ from amino acids and nucleotides.

Explain quorum sensing, and describe how it is related to biofilm formation.

___________ are small organic molecules that are required in minute amounts for metabolism.

Microaerophiles that grow best with a high concentration of carbon dioxide in addition to a low level of oxygen are called _______.

a. aerotolerant

b. capnophiles

c. facultative anaerobes

d. fastidious

The lowest temperature at which a microbe continues to metabolize is called its ___________ .

Why is agar used in microbiology?

Which of the following is not a growth factor for various microbes?

a. cholesterol

b. water

c. vitamins

d. heme

Cells that shrink in hypertonic solutions such as saltwater are responding to ___________ pressure.

a. Optimum growth temperature

b. Maximum growth temperature

c. Minimum growth temperature

d. Metabolic threshold

What is the difference between complex media and defined media?

Organisms that preferentially may thrive in icy waters are described as _______.

a. barophiles

b. thermophiles

c. mesophiles

d. psychrophiles

Obligate ___________ exist in salt ponds because of their ability to withstand high osmotic pressure.

Draw and label the four distinct phases of a bacterial growth curve. Describe what is happening within the culture as it passes through the phases.

Barophiles _______.

a. cannot cause diseases in humans

b. live at normal barometric pressure

c. die if put under high pressure

d. thrive in warm air