Chapter 14
Binary fission is asexual. What does this mean?
Asexual reproduction occurs when an organism replicates its own genome and divides into two daughter cells. THe daughter cells are a copy of the mother cell.
Why do the beta-lactam antibiotics affect sensitive baterial cells but not eukaryotic cells?
Beta-lactam antibiotics work by interfereing with the bacteria's ability to synthesize cell walls. Our eukaryotic cells are not affected because there is no cell wall in animal cells.
What is the difference between a Staphylococcus aureus colonization and a Staphylococcus aureus infection?
Colonization means the bacteria are carried on or in the body without causing disease; infections are associated with disease.
What is the evolutionary meaning of the term "fitness"?
Fitness describes the ability of an individual to survive and reproduce in a given environment. An organism that has a higher fitness will be able to reproduce and pass its genes to the next generation at a higher frequency than a less fit individual.
What are the two major mechanisms by which bacterial populations generate genetic diversity?
Gene exchange and mutation
A young athelete has a nasty skin infection caused by MRSA. How might he have contracted this infection?
MRSA can be passed from person to person by direct skin contact or touching contaminated surfaces. If the bacteria can find their way into a wound, they can get into the body and cause an infection. Athletes with cuts or scrapes can get MRSA from contact with other people or contaminated objects-towels.
In humans, very-large-birth-weight babies and very tiny do not survive as well as midrange babies. What kinds of selection is acting on human birth weight?
Stabilizing selection
The Term "MRSA" as it is used today refers to...
Staphylococcus aureus bacteria that are resistant to many antibiotics.
What is the environmental pressure in the case of antibiotic resistance?
The presence or absence of antibiotics in the environment
THe evolution of antibiotic resistance is an example of...
directional selection
Where is MRSA most likely to be a broblem?
in the bloodstream
