BIOL 2051 Exam 1 (CH 1-6)
what structures do prokaryotes lack that are present in eukaryotes?
- membrane bound nucleus - membrane bound organelles - cytoskeleton - endoplasmic reticulum/Golgi apparatus (membranous cytoplasmic structures)
Who provided the evidence needed to discredit the concept of spontaneous generation?
Louis Pasteur
A strain of Neisseria gonorrhoeae has undergone a mutation and is no longer able to make pili. Predict the most likely outcome? a) The bacteria will become less virulent and will not be able to readily establish infection. b) The bacterial strain will no longer be able to transport certain sugars into the cell. c) The bacteria will become more virulent and will more readily establish infection. d) The bacteria will become more resistant to antibiotics.
a (The bacteria will become less virulent and will not be able to readily establish infection)
You discover a new transport system used by a newly discovered bacterial species. The sugars that are transported using this system are phosphorylated as they enter the bacterial cell. You would describe this transport system as a(n) _____. a) group translocation b) passive diffusion c) facillitated diffusion d) micronutrient regulator
a (group translocation)
The study of microbiology includes all of the following except_____. a) plants b) viruses c)bacteria d) fungi e) algae f) all of the above
a (plants)
The Archaea generally lack which of the following that are normally found in gram-negative bacteria? a) Lipopolysaccharide b) All of the choices are correct. c) A complex peptidoglycan network d) Outer membrane
b (all choices)
A newly discovered microorganism has a circular chromosome that is complexed with histones, but not enclosed within a membrane. The plasma membrane lipids include glycerol dietethers and diglycerol tetraethers. There are no mitochondria or chloroplasts, but the cells do contain 70s ribosomes. This microbe most likely is a) a fungus. b) a bacterium. c) an archaeon. d) a protozoan.
c (an archaeon)
Which group of microbes contains organisms necessary for production of wine and bread? a) Archaea b) Bacteria c) Fungi d) Algae
c (fungi)
__________________ are hollow tube-like structures that hold some archaeal daughter cells together after cell division while____________ are grappling hook-like structures that appear to attach archaeal cells to surfaces.
cannulae; hami
Endospores are resistant to most environmental stressors because they have _____ complexed with calcium ions which stabilize DNA.
dipicolinic acid
external bacterial structure that is responsible for locomotion
flagellum
Molecules or regions of molecules that readily interact with water are said to be __________, whereas molecules or regions of molecules that are insoluble in water or do not readily interact with water are said to be hydrophobic.
hydrophilic
What disease did the first vaccination fight?
smallpox
A complete virus particle is called a
virion
Name one artificial method that is used to attack the bacterial cell wall.
B-lactam antibiotics (penicillin)
In what structure does respiration occur?
Cytoplasmic membrane (mitochondria!!)
The phospholipid of the plasma membrane in Bacteria is held together by what linkage?
Ester
T/F: Gram-positive bacteria have flagella with four basal body rings, while those of Gram-negative bacteria have only two.
False (Gram-positive bacteria have 2 basal body rings- Gram-negative have 4)
Which microscope typically uses dyes or antibodies?
Fluorescence
Antiseptic surgery was pioneered by
Joseph Lister
Name two structures that can be used for attachment in bacteria
Pili fimbriae (or capsule)
To avoid osmotic shock, extreme halophiles maintain a high intracellular concentration of what chemical?
Potassium (K+)
extreme halophiles maintain a high extracellular concentration of what chemical?
Sodium (Na+)
__________ is the process through which endospores are formed within a vegetative cell.
Sporulation
What is the most compelling reason why DNA, rather than RNA, evolved to be the storage repository for genetic information in cellular life forms? a) DNA molecules are more chemically stable than RNA molecules. b) DNA has deoxyribose rather than ribose. c) DNA is double-stranded rather than single-stranded.
a (DNA molecules are more chemically stable than RNA molecules)
Twitching motility involves a) type IV pili. b) periplasmic flagella. c) peritrichous flagella. d) monotrichous flagella.
a (type IV pili)
The movement of molecules across a membrane from an area of lower concentration to an area of higher concentration with the expenditure of energy is called
active transport
You did a gram stain but put too much ethanol. What will your smear look like under the microscope?
all cells would appear pink, assuming safranin was applied after
Check all of the following that showcases how microbes can be used by people. Check All That Apply: a) Production of breads b) Production of cheeses c) Production of antibiotics d) Production of vitamins e) Production of enzymes used for many different industrial applications
all of the above
Which of the following eukaryotes typically have cell walls? (Check all that apply.) a) Algae b) Protozoa c) Fungi d) Animals
all of the above
Lipids with polar and nonpolar ends are said to be
amphipathic
Cannulae are found in which domain of life?
archaea
Which of the following experiments is used to identify new pathogens? a) Stanley Miller experiment b) Koch postulates c) Pasteur's swan-neck experiment d) Endosymbiotic theory
b (Koch's postulates)
Which of the following bacterial groups is/are described CORRECTLY? a) Spirochetes - move by flagella movement b) Spirochetes - move by axial fibrils c) Spirochetes - move by axial fibrils and Nocardiae-form specialized dispersal cells on aerial mycelia d) Actinomycetes - reproduce by fragmentation e) Nocardiae - form specialized dispersal cells on aerial mycelia
b (Spirochetes - move by axial fibrils)
The bacterial flagellum moves ______. Multiple Choice a) in either a wave-like fashion or rotation that is powered by the proton motive force b) by rotation that is powered by the proton motive force c) in a wave-like fashion that is powered by the proton motive force d) by rotation that is powered by ATP e) in a wave-like fashion that is powered by ATP
b (by rotation that is powered by the proton motive force)
A feature unique to some archaeal plasma membranes is that they may a) consist of a lipid bilayer that lacks integral membrane proteins. b) consist of a lipid monolayer. c) contain sterols such as cholesterol. d) consist of a lipid bilayer with embedded proteins.
b (consist of a lipid monolayer)
You are trying to study the movement of a certain protozoan (protist, eukarya) species. What type of microscopy would be best? a) Bright-field b) Dark-field c)Electron microscopy d) two of the above e) all of the above
b (dark-field; Electron isn't necessary because the organism isn't extremely small; Bright-field would kill the organism and you wouldn't be able to study its movement)
Which of the following encodes its own capsid proteins? a) Prion b) Satellite virus c) Satellite RNA d) Satellite DNA
b (satellite virus)
Proteins function in modern cells as
both catalysts and structural elements
After performing a Gram stain of a mixed culture of Gram-positive and Gram-negative cells, you shout: "Oops, I forgot the iodine step!" What would you expect to see if you observed the slide under the microscope?
both pink Gram-positve and Gram-negative cells
Which virion release process is most often used by enveloped viruses?
budding
Choose the incorrect statement about Koch's postulates. a) Isolating the microorganism from all cases of the disease b)Isolation of the microorganism in pure culture in the lab c) Infecting an animal model without causing symptoms of the same disease d) Infecting a suitable animal model and causing symptoms of the same disease
c (Infecting an animal model without causing symptoms of the same disease)
Penicillin inhibits bacterial growth by preventing the cross-linking during peptidoglycan synthesis. Why does penicillin not inhibit growth of archaeal cells? a) Pencillin is unable to penetrate the S layer to reach the peptidoglycan layer underneath. b) Archaeal cells do not have a cell wall. c) Most archaeal cells have a cell wall, but it is not composed of peptidoglycan. d) Penicillin is unable to penetrate the lipid outer membrane that blocks access of penicillin to the peptidogycan crosslinking enzymes.
c (Most archaeal cells have a cell wall, but it is not composed of peptidoglycan)
The simplest viruses consist of a) Protein only. b) RNA, DNA and enzymes in a protein coat with a lipid envelope. c) RNA or DNA in a protein coat. d) RNA only. e) RNA or DNA in a protein coat covered with lipid envelope.
c (RNA or DNA in a protein coat)
Which of the following bacterial genera is/are described CORRECTLY? a) Corynebacterium - spore-forming rod and Clostridium - club-shaped rod b) Corynebacterium - spore-forming rod c)Vibrio - curved rod d) Clostridium - club-shaped rod e) Corynebacterium - spore-forming rod and Vibrio-curved rod
c (Vibrio - curved rod)
The Gram stain of a bacterial cell is based on the chemical properties of its ________.
cell wall
Ability to be distinguished from the surroundings
contrast
The spore layer containing peptidoglycan is the ______.
cortex
The proper sequence of reagents in the Gram stain procedure is
crystal violet, iodine, ethanol, safranin
Select a harmful effect that can result from bacterial colonization of the human body. a) Immune system development b) Production of vitamins c) Digestion of food d) Invasion of host cells
d (Invasion of host cells)
Who of the following developed a set of criteria that could be used to establish a causative link between a particular microorganism and a particular disease? a) Fracastoro b)Pasteur c)Lister d)Koch
d (Robert Koch)
Which of the following structures is NOT found in an endospore? a) Exosporium b) Coat c) Core d) Capsule
d (capsule)
The plasma membrane of eukaryotes contains all of the following EXCEPT a) sterols. b) phosphoglycerides. c) sphingolipids. d) peptidoglycan.
d (peptidoglycan)
Which of the following structures are external to both Bacterial and Archaeal cells? Multiple Choice a) Hami b) Ribosomes c) Peptidoglycan d) Pili
d (pili)
Which statement about flagellar structure is TRUE? a) The basal body is a short curved segment. b) The hook anchors the flagellum in the cell membrane and the filament extends out of the cell. c) The hook anchors the flagellum in the cell membrane. d) The filament extends out of the cell. e) The hook anchors the flagellum in the cell membrane,the basal body is a short curved segment, and the filament extends out of the cell.
d (the filament extends out of the cell)
Prions are of significance because they cause infections of
domestic animals and humans
Which of the following would be a reasonable estimate of the number of bacteria on earth? a) 5X10^1 b) 5X10^5 c) 5X10^10 d)5X10^18 e) 5X10^30
e (5X10^30)
Which of the following cocci cell arrangements is/are described CORRECTLY? a) Streptococci - Grape-like clusters of spherical cells b) Staphylococci - Chains of spherical cells c) Staphylococci - Chains of spherical cells and streptococci - Grape-like clusters of spherical cells d) Staphylococci - Chains of spherical cells, streptococci - Grape-like clusters of spherical cells, and diplococci - Pairs of spherical cells e) Diplococci - Pairs of spherical cells
e (Diplococci - Pairs of spherical cells)
Gliding motility in bacteria involves which of the following? a) Flagella b) Specialized cell-surface proteins, flagella, and slimy polysaccharides c) Slimy polysaccharides d) Specialized cell-surface proteins e) Specialized cell-surface proteins and slimy polysaccharides
e (Specialized cell-surface proteins and slimy polysaccharides)
The nucleic acids carried by viruses usually consist of
either DNA or RNA
The lipopolysaccharide (LPS) that is found in the outer membrane of gram-negative bacteria is also known as
endotoxin
the______is a membranous layer that can be found in some viruses.
envelope
The three domain system, comprising the bacteria, the _________, and the archaea, was devised in the 1970s by Carl Woese.
eukarya
Sterols are virtually always present in_________ but absent in_________
eukaryotic membranes; prokaryotic membranes
T/F: A temperate phage always lyses its host cell.
false
T/F: A viroid is a virus that lacks a capsid.
false
T/F: Although similar in function, the eukaryotic ribosome is generally smaller and more complex than the prokaryotic ribosome.
false
T/F: Cell walls of most Archaea and bacteria contain peptidoglycan.
false
T/F: Gram-positive bacteria have a structurally and chemically more complex cell wall than gram-negative bacteria.
false
T/F: Like prokaryotic cells, most eukaryotic cells have an external cell wall.
false
T/F: Microbiologists study a variety of organisms, but all are considered either Bacteria or Archaea.
false
T/F: Robert Koch developed a vaccine that could be used to prevent anthrax.
false
T/F: The Gram stain can only be performed on cultures grown in liquid media.
false
T/F: The leading cause of death in the US today are caused mainly by infectious diseases.
false
T/F: Viruses and bacteria were first cultured in the laboratory at about the same time.
false
T/F: Viruses are not generally studied by microbiologists because they are not classified as living organisms.
false
T/F: Viruses constitute the fourth domain of life in current biological classification schemes.
false
T/F: Viruses have typical cellular structure like other living organisms.
false
T/F: Gram-positive bacteria have a thinner layer of peptidoglycan than gram-negative bacteria.
false (Gram-positive have a thicker layer of peptidoglycan)
T/F: In an endospore, the protein coat forms a layer external to the exosporium.
false (exosporium is a layer formed external to the protein coat)
T/F: Edward Jenner's work in preventing rabies led to the use of the term vaccination to describe a type of procedure used in the prevention of disease.
false (he created first vaccine for smallpox from cowpox)
T/F: Most bacterial cells are around 10 to 100mm in size
false (largest bacteria is 0.7mm in size- smallest is 0.3um)
T/F: Endospores can only be formed by some Gram-negative bacteria.
false (only present in some Gram-positive bacteria)
T/F: Endospores are reproductive structures.
false (survival structures)
external bacterial structure that is responsible for bacterial attachment to surfaces
fimbriae
__________ is the main part of the process through which a vegetative cell is formed from an endospore.
germination
External structures that are found in Archaea but not Bacteria are _________.
hami
Enzymes needed to digest all types of macromolecules are found in
lysosomes
The apparent increase in size of an image
magnification
n endospore formation, when DNA condenses and aligns itself in the center of the cell, the cell is called a(n) ______.
mother cell
Can nucleic acids be broken down?
no. you will die
What is the most important macromolecule?
nucleic acid
In an enveloped virus, the part of the virus including the nucleic acid genome and the surrounding protein coat but not the envelope is called the
nucleocapsid
In prokaryotes, DNA is found mainly in the ________.
nucleoid
Name one double-membrane bound organelle that is found in eukaryotic cells.
nucleus (or mitochondria, chloroplast)
Genes whose expression (or abnormal expression) causes cancer are called
oncogenes
Membrane delimited intracellular structures that perform specific functions in cells are called
organelles
In addition, there is a (n) ______external to the Gram-negative bacterial peptidoglycan layer.
outer membrane
The Golgi apparatus is responsible for the
packaging of materials for excretion
The movement of molecules from an area of higher concentration to an area of lower concentration without the participation of specific carrier molecules is called
passive diffusion
The plasma membrane in Gram-negative bacteria contains only a thin layer of _______
peptidoglycan
The two layer cell wall of Gram-negative bacteria is separated from the plasma membrane by the _________
periplasmic space
Viroids are of economic significance because they cause disease in
plants
Most enveloped viruses use the host __________ membrane as their envelope source.
plasma
The cell wall of Gram-negative bacterial cells is external to the _______
plasma membrane
In general, what two structures are found in the cell envelope of bacteria?
plasma membrane cell wall
Bacterial cells that are variable in shape are called
pleomorphic
Cells with a relatively simple cell morphology that do not have a true membrane-delimited nucleus are called
prokaryotes
RNA serves to convert the information stored in DNA to ________.
protein
The power used by most bacterial flagellar motors is produced by
proton motive foce (PMF)
The ability to distinguish between two separate structures that are very close to one another
resolution
_______ are the site of protein synthesis in the cell.
ribosomes
Endoplasmic reticulum (ER) with many ribosomes attached is called __________ ER, whereas endoplasmic reticulum that is mostly devoid of ribosomes is called __________ ER.
rough; smooth
The bacterium E. coli swims in a straight line, called a __________, for a few seconds; then it stops, tumbles, then swims away in a new direction.
run
What microscope would be the best to use to view cell surface features of a specimen?
scanning electron microscope
external bacterial structure that is responsible for transferring DNA from one bacterial cell to another
sex pilus
the concept that living organisms arise from nonliving material is called
spontaneous generation
The formation of carbohydrate (CO2 fixation) in the dark reaction of photosynthesis, takes place in the
stroma
what is the biological function of endospores?
they enable organisms to endure extremes of temperature, drying, and nutrient depletion
What would be the best technique to prepare and view the internal structures of fungal hyphae?
transmission electron microscopy
T/F: Acetone can be used as the decolorizer in the Gram stain procedure.
true
T/F: All eukaryotes have a membrane-delimited nucleus.
true
T/F: Chloroplasts are the site for both the light and dark reactions of photosynthesis.
true
T/F: Mycoplasma pneumoniae lacks a cell wall and are pleomorphic in shape.
true
T/F: Some archaeal cells lack a cell wall.
true
T/F: Spirillum is a genus of spiral-shaped bacteria that move by flagella.
true
T/F: Spirochetes move in a screw-like manner that is mediated by bundles of flagella located in the cell's periplasmic space.
true
T/F: Spore formation is initiated when there is a scarcity of nutrients.
true
T/F: Sterol-like molecules called hopanoids are thought to be important for the structural integrity of many bacteria because of their suspected role in membrane stabilization.
true
T/F: The endosymbiotic hypothesis is generally accepted as the origin of two eukaryotic organelles: mitochondria and chloroplasts.
true
T/F: The membrane bound structure that contains the chromosomes of eukaryotes is called the nucleus.
true
T/F: in bacteria, poly-B-hydroxybutyrate and sulfur globules are inclusion bodies that can serve as an energy source.
true (as well as glycogen, polyphosphate, nd carboxysomes)
The term used to describe bacteria that are shaped like curved rods is
vibrios
Which type of phage always lyses its host cell?
virulent
Can you break down proteins for energy?
yes, carbs and lipids
