Chapter 4 Questions

Starting from a single bacterium, after six generations of binary fission, how many bacterial cells will be present?

64

Both human and bacterial cells divide by mitosis.

False

Cell division is triggered exclusively when cells attain a threshold mass.

False

DNA helicase is responsible for adding nucleotides to the growing end of the DNA.

False

In the U.S., the CDC estimates that ___ people suffer each year from some form of foodborne infection.

76 million

Most cultured bacteria tend to multiply by:

Binary Fission

Most bacteria reproduce by ______.

Binary fission

What happens to bacterial cells when their maximum growth temperature is exceeded?

Cells die more and more rapidly until all dead.

What food item is least likely to contain viable vegetative pathogens?

Chicken cooked to 170ºF

Which enzyme is NOT involved in DNA replication?

Gyrase

The FtsZ protein is needed to form the _____.

Needed to form the cross septum at the center of the cell.

According to the graph, what is the impact of cold temperatures on E. coli?

Rate of growth slows until cells cease to divide below 6ºC.

Cells must ______ their DNA prior to cell division.

Replicate

Which of the following environmental factors is the most important in influencing the growth rate of bacteria?

Temp*** Moisture Nutrients pH Oxygen Chemical inhibitors

Cells cannot begin a new round of replication until they have completely finished dividing.

True

The energy source for contraction of the FtsZ ring during cell division comes from _____.

hydrolysis of GTP