Bio 1101: Ch. 13 Quiz

In strains of bacteria that are not resistant to beta-lactam, which part(s) of the bacterial cells are disrupted by the antibiotic?

the cell walls

Which changes in a bacterial cell might reduce the effectiveness of beta-lactam antibiotics?

the presence of enzymes that are able to break down the antibiotic

Antibiotic-resistant strains of bacteria tent to first be found in hospitals. Which factor explains why this is the case?

Antibiotics are more likey to be present in hospitals, thus selecting for resistant strains.

A bacterial cell that is resistant to a particular antibiotic may spend a large amount of energy producing the modified proteins that are needed for resistance. In such a case, what would be the effect on this cell's fitness if no antibiotic was present?

Its fitness would be lower than other strains that lack resistance because it is spending energy that the resistant strains can use for other purposes, such as reproduction.

Which statement expresses the only real way to prevent the evolution of new antubiotic-resistant bacteria?

Stop using antibiotics entirely.

If you examine a natural population of bacteria, it is common to find some antibiotic-sensitive and some antibiotic-resistant strains, even if the population has never been exposed to any antibiotic/. Which explantation could account for this situation?

The resistant strain developed as a mutation and had no negative effect on fitness.

An organism's fitness depends on its ______

ability to survive and reproduce

The development and spread of a new gene for antibiotic-resistance in a population of bacterial that are exposed to that antibiotic would mean that trait is a(n)______

adaptation

Why aren/t humans populations evolving to produce immune systems that are able to fight off MSRA and other "superbugs?"

because the rate of human evolution is much slower than bacterial evolution

An individual who carries staph but isn't sick is referred to as ______

colonized

What is the evolutionary process that causes antibiotic-resistant bacteria to increase and antibiotic-senitive bacteria to decrease in an environment where antibiotics are present?

natural selection

A bacterial cell with which modification might be resistant to antibiotics such as methicillin?

the ability to produce an enzyme that breaks down the antibitic