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80 terms

Micro

Exam 1
STUDY
PLAY
Microorganisms are involved in which procces?
deomposition of organic material, infection, o2 production, food production.
Each of the following organisms would be considered a microbe EXCEPT
mushroom
The term used to describe a disease-causing microorganism is
Pathogen
Common commercial benefits of microorganisms include synthesis of
Antibiotics and insulin
Commercial utilization of microbial products has become increasingly popular due to their environmentally friendly nature. Removal of these products from the environment typically utilizes
enzymes.
The formal system for classifying and naming organisms was developed by
Carolus Linnaeus
In the name Staphylococcus aureus, aureus is the
genus
A prokaryotic cell may possess each of the following cellular components EXCEPT
nucleus
Which of the following is NOT associated with viruses?
Organelles
Protozoan motility structures include
cilia, flagella, and pseudopods.
Viruses are not considered living organisms because they
cant reproduce by themselves
The infectious agent that causes AIDS is
virus
Which of the following is NOT a domain in the three-domain system?
Animalia
Classification of organisms into three domains is based on
cellular organization.
Archaea differ from bacteria in that archaea
Lack peptidoglycan.
Who is credited with first observing cells?
Robert Hooke
Who is credited with first observing microorganisms?
Anton van Leeuwenhoek
Biogenesis refers to
development of life forms from prexisting life forms
If you were setting up an experiment to disprove spontaneous generation in a liquid medium, which of the following would be essential to the experiment?
using a sterile liquid and elimanting exposure to microorganism
The arguments supporting spontaneous generation were finally disproved by
Louis Pasteur
Regarding Louis Pasteur's experiments with the S-neck flask, which of the following statements is TRUE?
air exchange involved food source was provided, possibility of the cantamination was removed all prexisting microorganism were killed
The microbial process of converting sugars to alcohol is known as
fermentation
What is the type of bond holding hydrogen and oxygen atoms in the H2O molecule?
covalent bond
Which type of molecule contains the alcohol glycerol?
phospholipids
Which type of molecule is composed of (CH2O) units?
carbohydrate
Which type of molecule contains -NH2 groups?
Proteins
A scientist wants to perform a test that will indicate whether a nucleic acid sample is composed of RNA or DNA. Testing for the presence of which of the following is most appropriate in this situation?
uracil
Structurally, ATP is most like which type of molecule?
nucleic acid
What do genes consist of?
nucleic acids
Which molecule is composed of a chain of amino acids?
protein
Which are the primary molecules making up plasma membranes in cells?
Lipids
Radioisotopes are frequently used to label molecules in a cell. The fate of atoms and molecules in a cell can then be followed. Assume Saccharomyces cerevisiae is grown in a nutrient medium containing the radioisotope 35S. After a 48-hour incubation, the 35S would most likely be found in the S. cerevisiae's
proteins
Two glucose molecules are combined to make a maltose molecule. What is the chemical formula for maltose?
C12 H2 22 O11
What structure does light pass through after leaving the condenser in a compound light microscope?
Specimen
Which of the following pairs is mismatched?
basic dye and negative stain
Which of the following places the steps of the Gram stain in the correct order?1-Alcohol-acetone
2-Crystal violet
3-Safranin
4-Iodine
2413
Which of the following pairs is mismatched?
safranin and acidic dye
The purpose of a mordant in the Gram stain is to
prevent the crystal violet from leaving the cells
Which of the following places the steps in the correct sequence?
1-Staining
2-Making a smear
3-Fixing
2 3 1
A virus measures 100 nm in length. What is its length in μm?
.1 μm
Which of the following correctly traces the path of light through the compound microscope?
light source; condenser; specimen; objective lens; ocular lens
You are performing a Gram stain on gram-positive bacteria and you stop after the addition of the first dye. What is the appearance of the bacteria at this point?
purple
You are performing a Gram stain on gram-negative bacteria and you stop after the addition of the mordant. What is the appearance of the bacteria at this point?
purple
You are performing a Gram stain on gram-negative bacteria and you stop after the decolorizer step. What is the appearance of the bacteria at this point?
colorless
Assume you stain Bacillus by applying malachite green with heat and then counterstaining with safranin. Through the microscope, the green structures are
endospores
The purpose of the ocular lens is to
magnify the image form the objective lens
Which of the following statements is INCORRECT regarding prokaryotic cells?
They lack a plasma membrane
Each of the following statements concerning the gram-positive cell wall is true EXCEPT
protects the cell in a hypertonic enviorment
Which of the following statements best describes what happens when a bacterial cell is placed in a solution containing 5 percent NaCl?
water will move out
A gram-positive bacteria suddenly acquires resistance to the antibiotic methicillin. This trait most likely occurred due to
conjugtion
By which of the following mechanisms can a cell transport a substance from a lower to a higher concentration?
active transport
Which of the following is NOT a typical characteristic of most bacterial plasma membranes?
cholestrol
Which of the following have a cell wall?
Fungi
Which of the following pairs is mismatched?
A) endoplasmic reticulum internal transport
B) Golgi complex secretion
C) mitochondria ATP production
D) centrosome food storage
E) lysosome digestive enzymes
centrosomes and food storage
Which of the following organelles most closely resembles a prokaryotic cell?
Mitochondrion
Which drawing in Figure 4.1 is a tetrad?
oo
oo
Which drawing in Figure 4.1 possesses an axial filament?
A spiral
Antibiotics that target cell wall synthesis ultimately cause bacterial cell death as a result of
osmotic lysis.
Which of the following statements about gram-negative cell walls is FALSE?
they are sensitive to penicilin
Which of the following structures is NOT found in some prokaryotic cells?
cilium
Functions of the glycocalyx include all of the following EXCEPT
binary fission
Which structure acts like an "invisibility cloak" and protects bacteria from being phagocytized?
capsule
Which diagram of a cell wall is a gram-negative cell wall?
the thicker one
Which diagram of a cell wall possesses molecules responsible for symptoms associated with infection?
gram negative
Which diagram of a cell wall has a structure that protects against osmotic lysis?
both gram positive and gram negative protect against osmotic lysis
Which diagram of a cell wall is decolorized by alcohol?
gram negative
Which diagram of a cell wall is resistant to many antibiotics (e.g., penicillin)?
gram negtive
Which diagram of a cell wall contains teichoic acids?
gram positive
Which diagram of a cell wall contains porins?
gram negative
Which of the following statements is correct about diffusion?
It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.
In a hypertonic solution, a bacterial cell will typically
plasmoyzes
If cells are grown in media containing amino acids labeled with radioactive nitrogen (15N), most of radioactivity will be found in the cells'
DNA and proteins
A sample of milk is tested for its bacterial content in a plate count assay. A one-milliliter sample of the milk is diluted in a 1:10 dilution series. One milliliter of the third dilution tube is plated in a pour plate. After incubation, the plate has 54 colonies, indicating that the original milk sample contained
540,000
Salts and sugars work to preserve foods by creating a
hypertonic environment
Most fungi grow best at pH
5
During which growth phase will gram-positive bacteria be most susceptible to penicillin?
Log phase
Which of the following is the best definition of generation time?
the length of time needed for a cell to divide
at what pH does bacteria grow best?
7
what is facultative anaerobe in absence of O2
steady line up
what is obligated aerobe (hating)
steady down