MBIO 3401 FINAL EXAM SAMPLE QUESTIONS
AND ANSWERS | WITH COMPLETE SOLUTION
In the history of classification of microbes, who were the key historical contributors and
what were their key contributions?
van Leeuwenhoek: microscope/observation
Pasteur: disproved spontaneous generation
Koch: Four Postulates
Jenner: Vaccination
Fleming: antibiotics
Lister: carbolic acid: treat wounds and clean instruments
Semmelweis: doctors to wash hands w/ chlorine
Lady Montagu: infected patients w/ cowpox lesions
Frederick Griffith: transformation in bacteria
Watson and Crick: complementary bases and antiparallel nature of DNA
,Globally where are microbes able to grow and not grow?
-Microbes are ubiquitous:
-Hyperthermophiles: hot springs and undersea hydrothermal vents.
What are the typical size ranges of each major type of microbe?
-Eukaryotic: 2micrometers - 20cm
-Prokaryotic: 0.4 - 10 micrometers
-Virus: largest: 1.5 micrometers, but typically smaller than bacteria (acellular)
What microscope most easily visualize moving flagella?
Dark-field microscopy
What number of starting cells would produce any given number of final cells in log phase
growth after a specific number of generations?
Nt = N0 x 2n
final cell number = original cell number x number of generations
How is glucose transported into cells occur when energy sources (ATP/PEP etc) are not
available?
glucose transport via facilitated diffusion
1. Through Glucose transporters mainly by GLUT1-4
When and how can oxygen be toxic to cells, and how do cells mediate this toxicity?
, -Strict anaerobes can die in the presence of oxygen
-Aerotolerant anaerobes grow in O2 while retaining a fermentation-based metabolism
-Facultative anaerobes have the ability for fermentation metabolism and respiration
-Methanogens are poisoned by O2
What is the starvation response of cells?
-Enzymes are produced to increase the efficiency of nutrient gathering and protects cells'
macromolecules from damage
-In severe starvation, some members of a bacterial
population appear to sacrifice themselves to save others.
-They do so by undergoing what is termed programmed
cell death.
-The dying cells release nutrients that neighboring cells
use to survive.
How are petri dishes sterilized?
autoclaving or heating to high temp
Gaseous sterilization
Why don't bacteria grow in concentrated sugar solutions?
High sugar causes bacteria to lose water due to osmosis
What is the appearance and molecular structure of the sac around bacterial cells (based on
an image?)
AND ANSWERS | WITH COMPLETE SOLUTION
In the history of classification of microbes, who were the key historical contributors and
what were their key contributions?
van Leeuwenhoek: microscope/observation
Pasteur: disproved spontaneous generation
Koch: Four Postulates
Jenner: Vaccination
Fleming: antibiotics
Lister: carbolic acid: treat wounds and clean instruments
Semmelweis: doctors to wash hands w/ chlorine
Lady Montagu: infected patients w/ cowpox lesions
Frederick Griffith: transformation in bacteria
Watson and Crick: complementary bases and antiparallel nature of DNA
,Globally where are microbes able to grow and not grow?
-Microbes are ubiquitous:
-Hyperthermophiles: hot springs and undersea hydrothermal vents.
What are the typical size ranges of each major type of microbe?
-Eukaryotic: 2micrometers - 20cm
-Prokaryotic: 0.4 - 10 micrometers
-Virus: largest: 1.5 micrometers, but typically smaller than bacteria (acellular)
What microscope most easily visualize moving flagella?
Dark-field microscopy
What number of starting cells would produce any given number of final cells in log phase
growth after a specific number of generations?
Nt = N0 x 2n
final cell number = original cell number x number of generations
How is glucose transported into cells occur when energy sources (ATP/PEP etc) are not
available?
glucose transport via facilitated diffusion
1. Through Glucose transporters mainly by GLUT1-4
When and how can oxygen be toxic to cells, and how do cells mediate this toxicity?
, -Strict anaerobes can die in the presence of oxygen
-Aerotolerant anaerobes grow in O2 while retaining a fermentation-based metabolism
-Facultative anaerobes have the ability for fermentation metabolism and respiration
-Methanogens are poisoned by O2
What is the starvation response of cells?
-Enzymes are produced to increase the efficiency of nutrient gathering and protects cells'
macromolecules from damage
-In severe starvation, some members of a bacterial
population appear to sacrifice themselves to save others.
-They do so by undergoing what is termed programmed
cell death.
-The dying cells release nutrients that neighboring cells
use to survive.
How are petri dishes sterilized?
autoclaving or heating to high temp
Gaseous sterilization
Why don't bacteria grow in concentrated sugar solutions?
High sugar causes bacteria to lose water due to osmosis
What is the appearance and molecular structure of the sac around bacterial cells (based on
an image?)
