Questions and CORRECT Answers
Bacteria and archaea mainly reproduce by ---. - CORRECT ANSWER - binary fission
The complete sequence of events extending from formation of a new cell through the next
division is called the --- cycle. - CORRECT ANSWER - cell
What type of chromosome(s) do most bacterial cells contain? - CORRECT ANSWER -
Single circular
The site where replication of a bacterial chromosome begins is called the --- of replication. -
CORRECT ANSWER - origin
As the two chromosomes are replicated, the two origins ---. - CORRECT ANSWER -
move toward opposite cell poles
Which two groups of organisms reproduce by binary fission? - CORRECT ANSWER -
archaea
bacteria
Which process forms cross walls between daughter cells during cytokinesis? - CORRECT
ANSWER - septation
The cell cycle is ---. - CORRECT ANSWER - the events from formation of a new cell
through the next division
The component of the bacterial cell envelope that protects the cell from swelling and bursting
from turgor pressure is ---. - CORRECT ANSWER - peptidoglycan
,In general, which of the following microbes types tends to have a single circular chromosome
composed of DNA? - CORRECT ANSWER - bacteria
Increasing the size of peptidoglycan during cell division is a challenge because ---. - CORRECT
ANSWER - its strength must be maintained when new subunits are added
How many origins of replication are found on most bacterial chromosomes? - CORRECT
ANSWER - One
The group of enzymes responsible for peptidoglycan synthesis are notable for their binding to ---
. - CORRECT ANSWER - penicillin
Following initiation at the origin, DNA replication continues ---. - CORRECT ANSWER -
in both directions
Penicillin-binding proteins (PBPs) function to link strands of peptidoglycan together and
catalyze controlled degradation so that new units can be inserted during cell growth. The
enzymes that hydrolyze peptidoglycan are called ---. - CORRECT ANSWER - autolysins
The process of forming a cross wall between two daughter cells during the bacterial cell cycle is
called ---. - CORRECT ANSWER - septation
The cytoskeletal protein --- is needed for vibrioid cells to develop and maintain the curvature that
characterizes their shape. - CORRECT ANSWER - crescentin
One role of the cell wall in bacteria is to protect cells from bursting due to excessive ---. -
CORRECT ANSWER - turgor pressure
Which two of the following terms describe peptidoglycan? - CORRECT ANSWER - rigid
elastic
,Crescentin, the shape-determining protein of vibrioid cells, localizes to ---. - CORRECT
ANSWER - one side of the cell
The synthesis of peptidoglycan requires a group of enzymes called ---. - CORRECT
ANSWER - penicillin-binding proteins
Broth cultures that are inoculated and allowed to grow without the addition of fresh media are
called ---. - CORRECT ANSWER - batch cultures
Which group of enzymes is required for limited peptidoglycan degradation, so that new units can
be inserted during cell growth? - CORRECT ANSWER - Autolysins
Which is the term for the period of adaptation that typically occurs when fresh growth medium is
inoculated with a microbial culture? - CORRECT ANSWER - lag phase
Which protein is not important in maintaining the cell shape of vibrios? - CORRECT
ANSWER - MinC
The part of the microbial growth curve when cells are growing and dividing at their maximal rate
is called the --- phase. - CORRECT ANSWER - exponential (log)
Vibrioid-shaped cells derive their cell shape from ---. - CORRECT ANSWER -
asymmetric cell wall growth
The part of the microbial growth curve when cells reach their maximum density is called the ---
phase. - CORRECT ANSWER - stationary
Broth cultures that are grown without the addition of fresh media are called --- cultures. -
CORRECT ANSWER - batch
, The part of the microbial growth curve when cell density decreases is called the --- phase. -
CORRECT ANSWER - death
When fresh growth medium is inoculated with a microbial culture there is typically a period of
adaptation called the --- phase. - CORRECT ANSWER - lag
Which of the following phenomena is observed during long-term stationary phase? - CORRECT
ANSWER - natural selection
What is the term for the part of the microbial growth curve when cells are growing and dividing
at their maximal rate? - CORRECT ANSWER - exponential phase
The length of time that it takes a culture to double in cell number is called the ---. - CORRECT
ANSWER - generation time
The part of the microbial growth curve when cells reach their maximum density is called the ---.
- CORRECT ANSWER - stationary phase
Microorganisms that can grow under very harsh conditions are called ---. - CORRECT
ANSWER - extremophiles
For bacteria growing in batch culture conditions, the long-term stationary phase may last up to --
-. - CORRECT ANSWER - several years
Cells are likely to shrivel when placed in a --- solution. - CORRECT ANSWER -
hypertonic
The negative logarithm of the hydrogen ion concentration of a solution is its ---. - CORRECT
ANSWER - pH