Micro Biology week 1 Flashcards
What was Leeuwenhoek’s contribution to the science of microbiology?
He was the first to observe live microorganisms through a microscope.
How are the bacteria and the archaea different from all the other cellular microbes?
They have no nucleus.
A microorganism has the following characteristics: eukaryotic, multicellular, has cell walls, and grows in long filaments. What is its general classification?
fungus
You have isolated microorganisms that are green, photosynthetic, have a cell wall, and do NOT possess a nucleus. These organisms are __________.
bacteria
Which of the following is NOT an example of a fungus?
- mushrooms
- algae
- molds
- yeasts
algae
Which of the following is a true statement concerning bacteria and archaea?
- Bacteria reproduce asexually, while archaea reproduce sexually.
- While some bacteria are pathogenic to humans, no archaea are known to cause human diseases.
- Bacteria and archaea have identical types of cell walls.
- Bacteria are found only in extreme environments.
While some bacteria are pathogenic to humans, no archaea are known to cause human diseases.
All of the following individuals showed that cleanliness played a role in human disease EXCEPT __________.
- Lister
- Jenner
- Nightingale
- Semmelweis
Jenner
Koch’s work involving anthrax was significant because it was the first time __________.
a bacterium had been proven to cause a disease
Whose experiments supported the existence of a “life force”?
Needham
Put the following steps of Koch’s postulates in order:
a. The suspected infectious agent must be isolated and grown outside the host.
b. The suspected infectious agent causes the disease when it is introduced to a healthy, experimental host.
c. The suspected infectious agent must be found in every case of the disease.
d. The suspected infectious agent must be found in the diseased experimental host.
c, a, b, d
What is the vector for transmission of yellow fever?
Aedes aegypti mosquitoes
Why is this disease called “yellow fever”?
Patients have yellow mucous membranes and an elevated temperature.
Yellow fever is caused by a(n) _____.
virus
What is the best way to prevent the spread of yellow fever?
Drain standing water and sleep under mosquito netting.
Who is credited with the discovery of the cause of yellow fever?
Walter Reed
Which of the following is NOT a growing area of microbial study?
- ultraminiature technology
- communication within biofilms
- methods of disease
transmission - reducing antimicrobial resistance
methods of disease transmission
Which field of microbiology involves the study of microorganisms in their natural habitats?
environmental microbiology
Which of the following techniques could be used to produce a yeast capable of making viral proteins?
recombinant DNA technology
Which of the following fields of modern microbiology is NOT directly concerned with the genetic characteristics of a cell?
- bioremediation
- recombinant DNA technology
- molecular biology
- gene therapy
bioremediation
What is matter?
anything that takes up space and has mass
What is an atom?
the smallest chemical units of matter
What is an element?
composed of a single type of atom
Which of the following would contain teichoic acids?
a Gram-positive cell wall
Which of the following is NOT a basic process of life?
- responsiveness
- sexual reproduction
- growth
- metabolism
sexual reproduction
Which of the following is NOT a characteristic of a eukaryotic cell?
- can undergo transcription and translation simultaneously
- presence of a nuclear envelope
- contain chromosomes composed of DNA and histones
- presence of membrane-bound organelles
can undergo transcription and translation simultaneously
Which of the following statements about bacterial flagella is true?
Bacteria can only rotate flagella counterclockwise.
Flagella work by undulating.
Flagella can rotate 360 degrees.
Bacteria can only rotate flagella clockwise.
Flagella can rotate 360 degrees.
Taxis is
another word for stimulus.
caused by the undulating motion of a bacterium.
another term for bacterial tumbling.
movement towards or away from a stimulus.
movement towards or away from a stimulus.
Which of the following terms refers to a bacterium moving towards a light source?
Negative phototaxis
Negative chemotaxis
Positive chemotaxis
Positive phototaxis
Positive phototaxis
As a bacterium approaches a food source, one would expect
runs to become more frequent.
flagella to rotate clockwise more frequently.
flagella to stop spinning.
tumbles to become more frequent.
runs to become more frequent.
Why are receptors on the cell surface necessary for bacterial movement?
The receptors actually spin the flagella.
The receptors physically alter shape to steer the bacterium.
The receptors sense the stimulus and send signals to the flagella.
The bacterium contains receptors that are sensitive to light.
The receptors sense the stimulus and send signals to the flagella.
Which of the following scenarios is an example of bacterial motility?
A bacterium traveling through the air from a sneeze
A bacterium being removed from the skin during hand washing
A bacterium moving towards a food source
A bacterium moving towards a food source
Axial filaments are found on
staphylococci.
spirochetes.
streptococci.
rod-shaped bacilli.
spirochetes.
A bacterial cell possesses a glycocalyx. Which of the following is FALSE?
It will be less likely to dry out.
It will be engulfed more quickly by defensive cells of the host.
It will be able to attach to surfaces.
It will be more pathogenic.
It will be engulfed more quickly by defensive cells of the host.
Peptidoglycans are composed of sugars and _____.
teichoic acids
nucleic acids
lipids
amino acids
amino acids
One chain of alternating NAGs and NAMs is connected to another chain via _____.
tetrapeptides
enzymes
lipids
teichoic acids
tetrapeptides
One of the main differences between a Gram-positive and a Gram-negative bacterial cell wall is that the peptidoglycan portion of a Gram-positive cell wall is _____ as compared to a Gram-negative cell wall.
positively charged
thicker
more lipid rich
composed of a greater percentage of NAGs than NAMs
thicker
Within the peptidoglycan layer, the crossbridges that connect the chains of alternating sugar molecules extend between _____.
two N-acetylmuramic acid molecules
two glucose molecules
two N-acetylglucosamine molecules
an N-acetylmuramic acid and an N-acetylglucosamine
two N-acetylmuramic acid molecules
The peptidoglycan cell wall of bacteria is most analogous to _____.
a chain-link fence
a sugary candy shell
a rain coat
an impenetrable brick wall
a chain-link fence
What role do the teichoic acids play within the cell wall of Gram-positive bacteria?
They serve to stabilize the cell wall and hold it in place.
They serve as pores allowing the passage of ions, nutrients, and amino acids into the cell.
They act as crossbridges, holding the peptides and sugar molecules together.
They serve as adhesins, allowing bacteria to bind to one another.
They serve to stabilize the cell wall and hold it in place.
The region between the outer and inner membranes of a Gram-negative bacterial cell is known as the __________, and it is the location of enzymes that assemble peptidoglycan.
intramembranous space
lipopolysaccharide layer
cytoplasm
periplasmic space
periplasmic space
A patient is infected with Gram-negative bacteria and is experiencing only mild symptoms. When the patient is given an antibiotic causing lysis of the bacterial cells, he suddenly experiences an increase in inflammation and fever, as well as the formation of blood clots. What explanation best describes what happened?
The lysis of the cells releases NAG and NAM from the cell wall.
The lysis of the cells releases lipid A from the lipopolysaccharide layer.
The antibiotic is toxic and is affecting the patient adversely.
Any part of the bacterial cell wall released during lysis is seen as foreign and thereby elicits a severe immune response by the body’s immune system.
The lysis of the cells releases lipid A from the lipopolysaccharide layer.
Which of the following molecules would be blocked by a cell membrane?
Simple alcohols
Water
Ions
Dissolved oxygen
Ions
Hydrophobic molecules move across a membrane
by passive transport directly across the membrane.
through integral transport proteins.
by active transport directly across the membrane.
by passive transport directly across the membrane.
What is a hallmark of passive transport across cell membranes?
It may involve the use of transport proteins.
It occurs along an electrochemical gradient, and may involve the use of transport proteins.
It requires the use of ATP.
It occurs along an electrochemical gradient.
It cannot occur without assistance from an integral membrane protein.
It occurs along an electrochemical gradient, and may involve the use of transport proteins.
A positively charged sodium ion
would require the use of integral protein channels to pass through a cell membrane.
freely diffuses directly across the cell membrane.
would get stuck in the hydrophobic core of the membrane.
would require the use of integral protein channels to pass through a cell membrane.
Which of the following statements regarding active transport is false?
It powers the diffusion of water across the cell membrane.
It requires the use of a transport protein.
It requires ATP.
It powers the diffusion of water across the cell membrane.
Which of the following would NOT be found in the cytoplasm of a bacterial cell?
nucleoid
ribosomes
porins
endospores
porins
Which of the following would NOT be expected to be present in a biochemical analysis of an archaeal cell?
peptidoglycan
membrane proteins
membrane lipids
ribosomes
peptidoglycan
In a hypotonic environment, the volume of a plant cell enlarges as the cytoplasm pushes against the cell wall. Which organelles are most likely able to store that extra water?
vacuoles
vesicles
peroxisomes
mitochondria
vacuoles
How are the bacteria and the archaea different from all the other cellular microbes?
They have cell walls.
They have no nucleus.
They reproduce asexually.
They can move.
They have no nucleus.
Microbiologists study parasitic worms because __________.
they were not studied by early microbiologists
they usually contain bacteria and other microbes
they are microscopic as adults
they cause diseases that are diagnosed by finding microscopic eggs in clinical specimens
they cause diseases that are diagnosed by finding microscopic eggs in clinical specimens
Spallanzani’s experiments concerning spontaneous generation were NOT universally accepted because __________.
he did not give proper credit to Needham for his experiments
he did not know which bacteria were growing in his flasks
he eliminated air from his flasks by sealing them
he did not heat his infusion flasks long enough
he eliminated air from his flasks by sealing them
Put the following steps of Koch’s postulates in order: a. The suspected infectious agent must be isolated and grown outside the host.
b. The suspected infectious agent causes the disease when it is introduced to a healthy, experimental host.
c. The suspected infectious agent must be found in every case of the disease.
d. The suspected infectious agent must be found in the diseased experimental host.
c, b, a, d
c, a, b, d
d, b, c, a
a, d, c, b
c, a, b, d
Which of the following techniques could be used to produce a yeast capable of making viral proteins?
recombinant DNA technology
bioremediation
genome sequencing
gene therapy
recombinant DNA technology
Which of the following refers to the use of bacteria or other microbes to detoxify pollutants?
recombinant DNA technology
bioremediation
biochemistry
biotechnology
bioremediation
