chapter 2

How do spheroplasts and protosplasts differ?

Spheroplasts retain their outer membrane but protoplasts do not.

Which of the following contribute to the environmental resistance of bacterial endospores?

All of the choices are correct.

Which bacterial structure may survive if temperatures applied during food preservation processes are too low?

Endospores

Phosphorus can be obtained from organic sources only.

FALSE

Which of the following is not part of the process by which an endospore transforms to become a vegetative cell?

Induction

0. Which of the following is not a major class of growth factors?

Nucleic acids

All of the following are reasons why some scientists believe that the term "prokaryote" is a somewhat artificial designation and should be discarded except

Some bacteria have 80S ribosomes.

Nitrogen can be obtained from either organic or inorganic sources.

TRUE

The trace amounts of micronutrients needed by microorganisms are usually supplied as inadvertent contaminants in water and regular media components.

TRUE

strain of Neisseria gonorrhoeae has undergone a mutation and is no longer able to make pili. Predict the most likely outcome.

The bacteria will become less virulent and will not be able to readily establish infection.

Motile bacteria have been placed in an environment with a gradient of a chemical attractant. Which of the following behaviors would you predict?

The bacteria will both reduce tumbling frequency and increase run duration in the direction of the chemical.

A pathogenic bacterial species has mutated and is no longer able to synthesize a capsule. Which outcome would you predict?

The mutated bacteria will not be able to cause disease as readily.

Predict the change in 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.

Nutrients can be concentrated from dilute solutions by

active transport and group translocation.

76. Sulfur can be obtained from inorganic sources only.

false

Endospores are reproductive structures.

false

The original differentiation of prokaryotes and eukaryotes was based on structures found in prokaryotes that are lacking in eukaryotes.

false

A new protein has been described that transports a growth factor across the plasma membrane. This protein is most likely a/an:

integral membrane protein

Which of the following is not considered a micronutrient?

magneisum

The movement of molecules from an area of higher concentration to an area of lower concentration without the participation of specific carrier molecules is called

passive diffusion

Copper (Cu) is considered a micronutrient.

true

Different transport systems for the same nutrient that are part of the same organism are usually regulated in different ways.

true

Endotoxic shock, resulting from the release of endotoxin by bacteria infecting a patient, is only caused by Gram-negative bacteria.

true

Organisms usually have only a single transport system for any nutrient.

true

Permease proteins that aid in the transport of nutrients resemble enzymes in their specificity for the substance to be transported. Each carrier is selective and will transport only a closely related set of substances.

true

The extreme insolubility of ferric iron leaves little free iron available for transport into bacterial cells.

true

82. A wide variety of microorganisms are commercially used to manufacture _________ for human consumption.

vitamins