Question 1

A species of small lizard has three color forms,pale gray,brown,and black.In its original range,the colors of the rocky environment were mixed from pale gray to very dark,and the population had an even mix of all three color forms.The blending of colors with the environment helps the lizards hide from predators.A group of these lizards ended up on an island with only gray and black rocks.Eventually,the brown lizards disappeared.This is an example of

Accepted Answer

A)  artificial selection. 
B)  mutation. 
C)  diversifying selection. 
D)  directional selection. 
E)  stabilizing selection.

Question 2

What percentage of people carry antibiotic resistant strains of Staphylococcus aureus on their skin or in their noses?

Accepted Answer

A)  about 1% 
B)  about 5% 
C)  about 10% 
D)  about 12% 
E)  about 30%

Question 3

You are discussing antibiotic resistance with a friend,and the friend says the obvious solution is to develop stronger antibiotics.Do you agree? Why or why not?

Accepted Answer

The answer of You are discussing antibiotic resistance with a...

Question 4

Bacteria can divide as often as once every

Accepted Answer

A)  3 hours. 
B)  minute. 
C)  hour. 
D)  day. 
E)  20 minutes.

Question 5

Antibiotics should only be prescribed for

Accepted Answer

A)  fungal infections. 
B)  viral infections. 
C)  bacterial and fungal infections. 
D)  bacterial infections. 
E)  a flulike illness.

Question 6

All of the following are true of evolution,EXCEPT

Accepted Answer

A)  evolution leads to individuals with higher fitness than their predecessors. 
B)  individuals adapt their genes to improve survival. 
C)  the environment plays a large role in the process of evolution. 
D)  individuals with the most adaptive phenotypes have the most offspring. 
E)  evolution works through natural selection.

Question 7

MRSA can be contracted by

Accepted Answer

A)  skin-to-skin contact. 
B)  contact with open wounds. 
C)  contact with contaminated surfaces. 
D)  contact with contaminated soap and towels. 
E)  All of the above.

Question 8

What are the two mechanisms by which a bacterial cell can become resistant to antibiotics?

Accepted Answer

The answer of What are the two mechanisms by which...

Question 9

MRSA is caused by

Accepted Answer

A)  Streptococcus aureus. 
B)  a drug-resistant form of S. aureus. 
C)  S. aureus USA300. 
D)  a drug-resistant form of a virus. 
E)  a drug-resistant form of Methicillin aureus.

Question 10

Do you think drug resistance is more likely to develop in a species of bacteria that can double its population every 20 minutes or a species that doubles its population every 24 hours? Explain your answer.

Accepted Answer

The answer of Do you think drug resistance is more...

Question 11

Bacterial cell division is known as

Accepted Answer

A)  friction. 
B)  cytofission. 
C)  fusion. 
D)  fission. 
E)  nuclear fission.

Question 12

Staphylococcus aureus can cause

Accepted Answer

A)  boils. 
B)  sores. 
C)  pimples. 
D)  death. 
E)  All of the above.

Question 13

Two bacteria are genetically identical in all ways except that one has a gene that confers resistance to penicillin.These two cells are grown in the laboratory in cell-culture medium that is free of antibiotics.Will one cell reproduce faster than the other one? If so,which one? Explain your answer.

Accepted Answer

The answer of Two bacteria are genetically identical in all...

Question 14

Your friend has contracted a bacterial infection.Which of the following hypothetical drugs would you suggest as the best way to prevent an antibiotic-resistant allele from arising and spreading throughout the bacterial population in her body?

Accepted Answer

A)  a drug that prevents mutations but allows gene swapping 
B)  a drug that doesn't prevent mutations, but does prevent gene swapping with individuals of its own species 
C)  a drug that doesn't prevent mutations, but does prevent gene swapping with individuals of other species 
D)  a drug that doesn't prevent mutations, but prevents gene swapping with any individual of any species 
E)  a drug that prevents both mutations and gene swapping

Question 15

Binary fission is a form of

Accepted Answer

A)  nuclear division. 
B)  aerobic reproduction. 
C)  anaerobic reproduction. 
D)  asexual reproduction. 
E)  sexual reproduction.

Question 16

How would the resistance level of an antibiotic-sensitive variant in culture medium containing a minimal amount of antibiotics change over time?

Accepted Answer

A)  resistance will remain low 
B)  resistance will remain medium 
C)  resistance will remain high 
D)  resistance will change from high, to medium, and finally low 
E)  resistance will change from low, to medium, and finally high

Question 17

If the cell wall of Staphylococcus aureus fails to form properly,water will

Accepted Answer

A)  create a secondary wall around the cell. 
B)  drain out of the cell rapidly, causing it to dehydrate. 
C)  drown the bacteria. 
D)  rush into the cell, causing it to explode. 
E)  create a bridge of hydrogen bonds to repair the wall.

Question 18

Which of the following is NOT a possible way of transmitting a Staphylococcus aureus infection?

Accepted Answer

A)  sharing towels 
B)  skin-to-skin contact 
C)  contact sports 
D)  inhalation 
E)  All of the above ARE possible methods.

Question 19

MRSA in humans is an example of

Accepted Answer

A)  directional selection. 
B)  diversifying selection. 
C)  guided selection. 
D)  stabilizing selection. 
E)  uniform selection.

Question 20

What is the role of natural selection in evolution?

Accepted Answer

The answer of What is the role of natural selection...

Exam 14: Natural Selection and Adaptation Bugs That Resist Drugs