Microbiology Exam 1
Bacterial and archaeal ribosomes are known as _____ ribosomes, based on their sedimentation coefficient.
70S
Diglycerol tetraether lipids A. are a characteristic feature of thermophilic Archaea. B. tend to make the membrane less rigid. C. are found in some bacteria and some Archaea. D. form typical bilayer membranes in thermophilic Archaea of the genus Thermoplasma.
A. are a characteristic feature of thermophilic Archaea.
The protein coat surrounding the viral genome is called the A. capsule. B. capsid. C. matrix. D. envelope.
capsid
which of the following structures is not found in an endospore A. Capsule B. Coat C. Core D. Exosporium
capsule
as the magnification of a series of objective lens increases, the working distance A. increases. B. decreases. C. stays the same. D. cannot be predicted.
decreases
which term is most inclusive A. Microbial species B. Microbial strain C. Biovars D. Serovars
microbial species
26. Protein filaments with a diameter of 4-7 nm that play a role in cell movement and shape change are called A. microtubules. B. microfilaments. C. intermediate filaments. D. mycelia.
microfilaments
in transmission electron microscopy, spreading a specimen out in a thin film with uranyl acetate, which does not penetrate the specimen, is called A. freeze-etching. B. simple staining. C. shadow staining. D. negative staining.
negative staining
Basic dyes such as methylene blue bind to cellular molecules that are: a. hydrophobic b. negatively charged c. positively charged d. aromatic
negatively charged
which of the following is not a major class of growth factors? A. Amino acids B. Purines and pyrimidines C. Vitamins D. Nucleic acids
nucleic acids
Three the SSU rRNA sequences of 3 organisms have been compared. For organisms 1 and 2, two of the twelve nucleotides in the sequence are different. For organisms 1 and 3, six of the twelve nucleotides are different. Which organism has greater evolutionary distance from organism 1?
organism 3
While each of these processes are believed to have evolved prior to aerobic respiration, which one is the most critical process, without which aerobic respiration could never have developed? A. Oxygenic photosynthesis B. Anoxygenic photosynthesis C. Alcohol fermentation D. Lactic acid fermentation
oxygenic photosynthesis
31. The Golgi apparatus is responsible for the A. the assembly of ribosomes. B. packaging of materials for excretion. C. formation of mesosomes. D. replication of chromosomes.
packaging of materials for excretion.
If the objective lenses of a microscope can be changed without losing focus on the specimen, they are said to be A. equifocal. B. totifocal. C. parfocal. D. optifocal.
parfocal
movement of molecules from an area of high concentration to an area of low concentration without participation of a carrier molecule A. facilitated diffusion. B. osmosis. C. passive diffusion. D. active transport
passive diffusion
Viral capsid protein subunits are called
protomers
Adult T-cell leukemia is thought to be caused by
retroviruses.
all of the following are reasons why some scientists believe that the term "prokaryote" is a somewhat artificial designation and should be discarded except A. Some bacteria have internal membranous structures. B. Some bacteria have their genetic material enclosed within a membrane. C. Some bacteria have 80S ribosomes. D. Many bacterial have cytoskeletal elements.
some bacteria have 80S ribosomes
If immersion oil was replaced with water, what would happen? A. The refractive index would increase, improving resolution. B. The refractive index of water would be greater than air but less than oil, improving resolution less than oil. C. The refractive index of water would be less than that of air, decreasing resolution. D. There would be no difference.
the refractive index of water would be greater than air but less than oil, improving resolution less than oil
predict the change in surface and volume of a spherical cell if the diameter of the cell doubles
the surface area will increase by a factor of 4, while the volume will increase by a factor of 8
What is the minimum number of phage that can initiate the development of a plaque in a bacterial lawn?
1
Virion size ranges from A. 1-40 nm. B. 10-400 nm. C. 600-1,000 nm. D. 1,000-10,000 nm.
10-400 nm
0.2 mls of a 10-4 dilution of a virus preparation yields 90 plaques. What is the number of PFU per ml in the undiluted virus preparation? A. 9.0 105 B. 4.5 106 C. 4.5 107 D. 9.0 108
4.5 106
The primary lipid components of the membranes of extreme thermophiles are A. sulfolipids. B. cholesterol. C. 40 carbon diglycerol tetraethers. D. 20 carbon diglycerol diethers.
40 carbon diglycerol tetraethers
a 30x objective and 20x ocular produce a total magnification of
600x
Which type of membrane transport is most important for nutrient acquisition in nutrient poor environments? A. Simple diffusion B. Facilitated diffusion through channel proteins C. Facilitated diffusion through membrane carrier proteins D. Active transport
Active transport
Which of the following eukaryotes typically have cell walls? (Check all that apply.) _____ Algae _____ Protozoa _____ Fungi _____ Animals
Algae and Protozoa
Viral envelopes are composed of A. proteins. B. lipids. C. carbohydrates. D. All of the choices are correct.
All of the above
Which of the following can be used to cultivate plant viruses? A. Cultures of separated plant cells B. Whole plants C. Plant protoplast cultures D. All of the choices are correct.
All of the above
Which of the following diseases is (are) caused by prions? A. Scrapie B. Mad cow disease C. Kuru and Creutzfeldt-Jakob Disease D. All of the choices are correct.
All of the above
Archaeal membranes contain which of the following lipids? A. Phospholipids B. Sulfolipids C. Glycolipids D. All of the choices are correct.
All of the choices are correct
Some researchers have suggested that archaeal flagella be renamed as archaella because A. they are more slender than bacterial flagella. B. some archaeon flagella don't have hooks. C. All of the choices are correct. D. archaean flagella are composed of more than one type of flagellin subunit. E. archaean flagella are solid and not hollow.
All of the choices are correct
The Archaea generally lack which of the following that are normally found in gram-negative bacteria? A. Outer membrane B. A complex peptidoglycan network C. Lipopolysaccharide D. All of the choices are correct.
All of the choices are correct
Which of the following contribute to the differences between the members of the Domain Archaea and the Domain Bacteria? A. Archaea lack muramic acid. B. Archaea have isopranyl glycerol ethers rather than fatty acid esters in their membrane lipids. C. Archaea differ from bacteria in their tRNA composition, ribosome structure, and antibiotic sensitivity. D. All of the choices are correct.
All of the choices are correct
Animal viruses have been cultivated in A. suitable host animals. B. embryonated eggs. C. tissue cultures (monolayers of animal cells). D. All of the choices are correct.
All of the choices are correct.
Which of the following are characteristics of hydrogenosomes that distinguish them from mitochondria? A. Hydrogenosomes generate ATP by fermentation. B. The inner membrane of hydrogenosomes is not highly folded. C. Hydrogenosomes have no DNA. D. All of the above
All of the choices are correct.
You are working with a newly described microorganism that has flagella that are solid, 10 nm in diameter, and composed of more than one type of flagellin subunit. Based on the type of flagella, which type of organism is this? A. Archaea B. Bacteria C. Protozoa D. Algae
Archaea
41. The nucleolar organizer is a part of a specific chromosome that directs the synthesis of A. transfer RNA (tRNA). B. ribosomal RNA (rRNA). C. messenger RNA (mRNA). D. heterogeneous nuclear RNA (hnRNA).
B. ribosomal RNA (rRNA).
The use of enrichment cultures and selective media was pioneered by
Beijerinck
Which types of eukaryotic cells have cell walls composed of cellulose? A. Algae B. Fungi C. Plants D. Protozoa E. Both algae and plants
Both algae and plants
proteins function in modern cells as A. catalysts. B. hereditary information. C. structural elements. D. both catalysts and structural elements.
Both catalysts and structural elements.
Which virion release process is most often used by enveloped viruses? A. Lysis B. Facilitated diffusion C. Budding D. Diffusion through channel protein
Budding
43. The nucleolus plays a major role in synthesis of A. mRNA. B. tRNA. C. rRNA. D. transcription activation proteins.
C. rRNA.
_________ 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 A. Pili; hami B. Cannulae;hami C. Hami; fimbriae D. Cannulae; pili
Cannulae; hami
37. Which of the following parts of the Golgi complex receives materials from the ER?
Cis face
which of the following is not considered a macronutrient?
Cobalt
Where is the glycolysis pathway located in a cell? A. Cristae of the mitochondria B. Matrix of the mitoconddria C. Smooth endoplasmic reticulum D. Cytoplasm
Cytoplasm
what is the most compelling reason why DNA evolved to be the storage repository for genetic info in cellular life forms? A. DNA has deoxyribose rather than ribose. B. DNA molecules are more chemically stable than RNA molecules. C. DNA is double-stranded rather than single-stranded.
DNA molecules are more chemically than RNA molecules
Which mechanism of nutrient acquisition is not seen in bacteria? A. Simple diffusion B. Facilitated diffusion C. Endocytosis D. Active transport E. Group translocation
Endocytosis
Which cell type ranges in size from about 10 - 100 µm, has 80s ribosomes, and has internal compartments bounded by membranes? A. Archaea B. Bacteria C. Eukarya
Eukarya
Which of the following has flagella that contain microtubules ? A. Archaea B. Bacteria C. Eukarya
Eukarya
Which of the following has flagella that wave back and forth? A. Archaea B. Bacteria C. Eukarya
Eukarya
in a search for new antibiotics, a previously unknown organism has been recovered from the soil. It is nonmotile and is composed of long threadlike structures formed from nucleated cells. It is not-photosynthetic and absorbs its nutrients. This organism will most likely be classified among the
Eukaryotes (Fungi)
a student is observing microorganisms in a sample of pond water. one organism of interest has an obvious nucleus, small oval structures containing a green pigment, and does not appear to be motile. in which of the following groups would this microbe most likely be classified? A. Eukaryotes (Fungi) B. Eukaryotes (Algae) C. Bacteria D. Archaea E. Eukaryotes (Protozoa)
Eukaryotes (algae)
a student is observing microorganisms in a sample of pond water. one organism of interest has an obvious nucleus and has been moving rapidly during observation and appears to have rows of cilia along its surface. in which of the following groups would this microbe most likely be classified? A. Eukaryotes (Fungi) B. Eukaryotes (Algae) C. Bacteria D. Eukaryotes (Protozoa)
Eukaryotes (protozoa)
Which of the following is not true of viroids? A. Viroids are small circular ssRNA molecules. B. Viroids have no protein capsids. C. Viroid RNA does not serve as mRNA nor does it direct the synthesis of mRNA. D. Extracellular viroids have a lipid bilayer envelope.
Extracellular viroids have a lipid bilayer envelope.
18. The genetic code is expressed differently in bacterial and archaeal cells than in eukaryotic cells
False
5. Coated pits containing clathrin do not permit concentration of ingested macromolecules prior to endocytosis.
False
9. Although similar in function, the eukaryotic ribosome is generally smaller and more complex than the prokaryotic ribosome.
False
A PrPc protein can convert a PrPSc to a PrPc.
False
A temperate phage always lyses its host cell.
False
Although developed over 100 years ago, Koch's postulates continue to be used successfully in all known human infectious diseases.
False
Archaeal and Bacterial pili are identical in structure and function.
False
Archaeal flagella are superficially similar to bacterial flagella, although archaeal flagella are much thicker than bacterial flagella.
False
Archaeons power their flagella by proton motive force, whereas bacteria empower their flagella by ATP hydrolysis
False
Bacteria growing at lower temperatures have more saturated fatty acids in their membranes.
False
Bacterial viruses are so named because they have prokaryotic cell structures similar to their bacterial hosts.
False
Because transmission electron microscopy uses electrons rather than light, it is not necessary to stain biological specimens before observing them
False
Cell walls of most Archaea and bacteria contain peptidoglycan.
False
During the assembly of the flagellar filament, the flagellin protein monomers assemble at the cell proximal base of the flagellum.
False
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
Endospores are reproductive structures.
False
Extant microorganisms are organisms from the fossil record that are no longer present on Earth today.
False
Gram-positive bacteria have a structurally and chemically more complex cell wall than gram-negative bacteria
False
Gram-positive bacteria have a thinner layer of peptidoglycan than gram-negative bacteria.
False
If you remove the peptidoglycan layer from a Gram-positive cell, it would still stain purple with a Gram stain.
False
Immersion oil is used to prevent a specimen from drying out
False
In a plaque assay, the number of infectious virions is usually identical to the number of virus particles present.
False
In terms of membrane lipids, the plasma membrane of archaeons are more similar to those of the eukaryotes than to membranes of bacteria.
False
Koch's postulates were instrumental in establishing that Mycobacterium leprae is the cause of leprosy
False
Laboratory animals must be used to determine lethal and infectious doses of viruses.
False
Like bacteria and eukaryotic microorganisms, most viruses can be cultured using artificial media.
False
Like prokaryotic cells, most eukaryotic cells have an external cell wall.
False
Microbiologists study a variety of organisms, but all are considered either Bacteria or Archaea
False
Negative staining facilitates the visualization of bacterial capsules that are intensely stained by the procedure.
False
Organisms usually have only a single transport system for any nutrient.
False
Phosphorous can obtained from organic sources only.
False
Robert Koch developed a vaccine that could be used to prevent anthrax
False
Sedimentation coefficients are proportional to the molecular weight of a particle and are not affected by the volume and shape of the particle.
False
Sulfur can be obtained from inorganic sources only.
False
The Gram-staining procedure is widely used because it allows rapid identification of a microorganism with little additional testing.
False
The cell membrane is a rigid structure that provides bacteria with their characteristic shapes.
False
The distribution of lipids in the plasma membrane of eukaryotes is symmetrical
False
The earliest microbial fossils that have been found are dated from approximately 4.5 million years ago.
False
The hydrocarbons found in the membranes of the archaea are identical to those found in bacteria
False
The layers of peptidoglycan of the bacterial cell wall can be cross-linked by peptide intrabridges or by direct cross-linking.
False
The original differentiation of prokaryotes and eukaryotes was based on structures found in prokaryotes that are lacking in eukaryotes.
False
The presence or absence of an envelope is not useful in classifying viruses because any given virus may at one time have an envelope and at another time not have an envelope.
False
The rotation of bacterial flagella is powered by ATP hydrolysis.
False
There are no known human diseases that have been linked to prions.
False
Unlike members of the Bacteria, most archaeans have linear chromosomes.
False
Viruses and bacteria were first cultured in the laboratory at about the same time
False
Viruses constitute the fourth domain of life in current biological classification schemes.
False
Viruses have typical cellular structure like other living organisms.
False
Viruses infecting protists, including algae, have never been detected.
False
Zinc is considered a macronutrient
False
A microscope that exposes specimens to ultraviolet, violet, or blue light and forms an image with the light emitted at a different wavelength is called a __________ microscope. A. phase-contrast B. dark-field C. scanning electron D. fluorescence
Fluorescence
33. Which of the following organelles is involved in the modification, packaging, and secretion of materials? A. Lysosomes B. Golgi apparatus C. Mitochondria D. Centrioles
Golgi apparatus
If you FORGOT the decolorization step while performing a Gram stain, which outcome would you expect? A. Gram-positive bacteria would stain pink. B. Gram-negative bacteria would stain purple. C. Gram-negative bacteria would be unstained. D. Gram-positive bacteria would be unstained.
Gram-negative bacteria would stain purple
Which of the following has been associated with a form of liver cancer?
Hepatitis B virus
Which of the following is/are necessary for the replication of a satellite virus? A. Host cell only B. Helper virus only C. Prion only D. Host cell and helper virus
Host cell and helper virus
Virus morphology does not include which of the following characteristics? A. Size B. Shape C. Presence or absence of an envelope D. Host range
Host range
Which of the following must leave the nucleus via the nuclear pore complexes? A. Immature ribosomal subunits B. tRNA C. mRNA D. Immature ribosomal subunits, tRNA, and mRNA
Immature ribosomal subunits, tRNA, and mRNA
For a temperate phage to produce more phage, which of the following must happen? A. Lysogeny B. Induction C. Lysogenic conversion D. Prophage formation
Induction
Which of the following is most true of a viral DNA genome? A. It uses the same four nitrogenous bases found in prokaryotic and eukaryotic DNA. B. It may have the normal bases found in prokaryotic and eukaryotic DNA, or it may have one or more unusual bases. C. It is usually composed of unusual bases unique to viruses. D. Viruses do not use DNA for their genome.
It uses the same four nitrogenous bases found in prokaryotic and eukaryotic DNA.
A drug, colchicine, can be added to cells in culture and it stops the polymerization of microtubules. What effect would this have on mitosis?
It would slow or block mitosis by interfering with the spindle apparatus function.
Antiseptic surgery was pioneered by A. Pasteur. B. Lister. C. Jenner. D. Kitasato.
Lister
elements that are required in relatively large amounts by microorganisms are called A. multivitamins. B. meganutrients. C. macronutrients. D. macromolecules.
Macronutrients
Who of the following first discovered that some blood leukocytes could engulf disease-causing bacteria? A. von Behring B. Meister C. Metchnikoff D. Ivanowski
Metchnikoff
Penicillin inhibits bacterial growth by preventing the cross-linking during peptidoglycan synthesis. Why does penicillin not inhibit growth of archaeal cells? A. Archaeal cells do not have a cell wall. B. Most archaeal cells have a cell wall, but it is not composed of peptidoglycan. C. Penicillin is unable to penetrate the lipid outer membrane that blocks access of penicillin to the peptidogycan crosslinking enzymes. D. Pencillin is unable to penetrate the S layer to reach the peptidoglycan layer underneath.
Most archaeal cells have a cell wall, but it is not composed of peptidoglycan
Which type of virus is most likely to be released by lysis of the host cell? A. Enveloped virus B. Non-enveloped virus
Non-enveloped virus
The first surgical antiseptic to be used was A. iodine. B. ethanol. C. phenol. D. None of the choices are correct.
Phenol
Which of the following structures are external to both Bacterial and Archaeal cells? A. Ribosomes B. Hami C. Pili D. Peptidoglycan
Pili
Which of the following is most likely synthesized on free ribosomes? A. Polypeptide chains that form enzymes which function in glycolysis B. Electron carriers of the electron transport chain C. Polypeptide chains that form immunoglobulin molecules D. Lysosomal enzymes
Polypeptide chains that form enzymes which function in glycolysis
The most notable difference between PrPC (normal protein) and PrPSc (prion protein) is
PrPc folds appropriately whereas PrPSc does not fold correctly.
You are studying a newly discovered prokaryotic microorganisms and are attempting to determine whether it will classified in the domain Bacteria or in the domain Archaea. All of the following would be helpful in making that distinction except A. Sequence of small subunit ribosomal RNA B. Type of membrane lipids C. Presence or absence of peptidoglycan in cell walls D. Presence or absence of double-stranded circular DNA genome
Presence or absence of double-stranded circular DNA genome
which molecule is believed to have preceded the other three during the evolution of life
RNA
The simplest viruses consist of A. RNA only. B. Protein only. C. RNA or DNA in a protein coat. D. RNA or DNA in a protein coat covered with lipid envelope. E. RNA, DNA and enzymes in a protein coat with a lipid envelope.
RNA or DNA in a protein coat
In which of the following stages of the viral infectious cycle do enveloped viruses usually acquire their envelopes? A. Penetration B. Component biosynthesis C. Assembly D. Release
Release
Which of the following encodes its own capsid proteins? A. Satellite virus B. Satellite DNA C. Satellite RNA D. Prion
Satellite virus
Which of the following is the most unique aspect of archaeon cell envelopes? A. The plasma membrane is composed of phospholipids B. The cell walls contain a modified type of peptidoglycan C. Archaeon capsules can be composed of protein or polysaccharide. D. Some archaeons have lipid monolayers in their plasma membrane.
Some archeons have lipid monolayers in their plasma mebrane
Which statement correctly explains the Gram stain reaction of archaeal cells? A. They are Gram-positive due to the pseudomurein layer in their cell walls. B. They are Gram-negative due to the lack of peptdoglycan in their cell walls. C. They don't stain - basic dyes used in the Gram stain don't adhere to archaeal cells. D. Some are Gram-positive and some are Gram-negative due to the diverse chemical structure.
Some are Gram-positive and some are Gram-negative due to the diverse chemical structure
Which statement correctly describes archaeal cell walls? A. Some have an outer layer of complex polysaccharide. B. Some have an outer layer of protein. C. Many have peptidoglycan. D. Some have an outer layer of complex polysaccharide and some have an outer layer of protein.
Some have an outer layer of complex polysaccharide and some have an outer layer of protein
Which of the following represent(s) the way(s) in which enveloped viruses acquire their envelopes? A. Budding through the plasma membrane. B. Budding through internal cellular membranes. C. Viral enzymes are responsible for production of the envelope. D. Some viruses bud through the plasma membrane while other bud through internal cellular membranes.
Some viruses bud through the plasma membrane while other bud through internal cellular membranes.
How do spheroplasts and protosplasts differ?
Spheroplasts retain their outer membrane but protoplasts do not.
Which cellular shape is seen among members of domain Bacteria that is not found among the domain Archaea? A. Cocci B. Bacilli C. Comma shaped D. Spiral or corkscrew shapes
Spiral or corkscrew shapes
A strain of Neisseria gonorrhoeae has undergone a mutation and is no longer able to make pili. Predict the most likely outcome. A. The bacterial strain will no longer be able to transport certain sugars into the cell. B. The bacteria will become more virulent and will more readily establish infection. C. The bacteria will become more resistant to antibiotics. D. The bacteria will become less virulent and will not be able to readily establish infection.
The bacteria will become less virulent and will not be able to readily establish infection.
Select the correct statement about archaeal ribosomes A. Archaeal ribosomal proteins are more similar to bacterial ribosomal proteins than to eukaryotic ribosomal proteins. B. Archaeal ribosomes are susceptible to antibiotics, similar to bacterial ribosomes. C. Archaeal ribosomes have subunits that are identical in shape and chemical components to those of bacteria. D. The chemical components of archaean ribosomes are more similar to those of eukaryotic ribosomes than to those of bacterial ribosomes.
The chemical components of archaean ribosomes are more similar to those of eukaryotic ribosomes than to those of bacterial ribosomes
what is the most compelling reason why protists are not considered to be a taxonomic group? A. They are not cellular life forms. B. They are too small to be included among the eukaryotes. C. The group includes both prokaryotic and eukaryotic cell types. D. The organisms often included in this group are very diverse and don't form a cohesive taxon.
The organisms often included in this group are very diverse and don't form a cohesive taxon
Which of the following is useful in distinguishing between prokaryotic and eukaryotic cells? A. The use of DNA for the storage of genetic information B. The presence of ribosomes for the synthesis of proteins C. The presence of membrane-delimited organelles within the cytoplasm D. All of the choices are correct.
The presence of membrane-delimited organelles within the cytoplasm
Which of the following is/are not true about viral envelopes? A. The envelope proteins are virus specific. B. The envelope lipids and carbohydrates are derived from the host. C. They are typical lipid monolayers with embedded viral proteins. D. The envelope proteins are virus specific and the envelope lipids and carbohydrates are derived from the host.
They are typical lipid monolayers with embedded viral proteins.
Which of the following is true of viruses in the extracellular phase? A. They possess many different enzymes. B. They can reproduce independently of living cells but only at a slow rate. C. They behave as a macromolecular complex and are no more alive than are ribosomes. D. They possess many different enzymes and they can reproduce independently of living cells but only at a slow rate.
They behave as a macromolecular complex and are no more alive than are ribosomes.
Which of the following is not true about archaeal ribosomes? A. They are 70S like bacterial ribosomes. B. They may possess ribosome binding sites homologous to bacterial Shine-Dalgarno sequences. C. They have similar antibiotic sensitivities to those of bacteria. D. All of these are true about archaeal ribosomes.
They have similar antibiotic sensitivities to those of bacteria
Which is not true of viruses? A. They can exist in an intracellular or extracellular phase. B. They infect animal and plant cells only. C. They can be observed with an electron microscope. D. They are acellular. E. They replicate only inside host cells.
They infect animal and plant cells only.
Which of the following is not a mechanism by which viruses cause cancer?
They produce defective interfering particles.
One type of archaeon, Haloquadratum walsbyi, is shaped like a postage stamp with dimensions of 2 micro m x 3 micro m x 0.25 micro m. What advantage would this shape provide?
This shape increases the surface to volume ratio enabling more efficient nutrient uptake
Small internal cell structures are best visualized with a A. light microscope. B. dark-field microscope. C. transmission electron microscope. D. flagellar microscope.
Transmission electron microscope
10. The nucleolus is a highly active region of the nucleus that is required for synthesis of ribosomes
True
13. Electron transport reactions that occur in the mitochondria of eukaryotes take place on the inner membrane of that structure.
True
20. The major difference between the vacuoles of eukaryotes and the inclusion bodies of prokaryotes is that the former are membrane-bound, whereas the latter are not.
True
4. The endoplasmic reticulum is mostly devoid of ribosomes (smooth) when cells are producing large quantities of lipid.
True
8. The membrane bound structure that contains the chromosomes of eukaryotes is called the nucleas
True
A eukaryotic flagellum can either push a cell through a liquid environment or pull it through depending on the undulating pattern of movement.
True
A light microscope with an objective lens numerical aperture of 0.65 is capable of allowing two objects 400 nm apart to be distinguished when using light with a wavelength of 420 nm.
True
A substage condenser is used to focus light onto the specimen, which increases the resolution of a light microscope
True
Agastino Bassi demonstrated that a type of silkworm disease was caused by a fungus and proposed that many diseases are caused by microorganisms.
True
Almost all known plant viruses are RNA viruses.
True
Available evidence is consistent with the proposal that prion diseases are caused by infectious proteins.
True
Confocal microscopes can be used to create three-dimensional images of cell structures
True
Copper is considered a micronutrient
True
Creutzfeldt-Jacob disease is known to have been transmitted by surgical instruments and transplanted nerve tissue.
True
Different transport systems for the same nutrient that are part of the same organism are usually regulated in different ways.
True
Endotoxic shock, resulting from the release of endotoxin by bacteria infecting a patient, is only caused by Gram-negative bacteria.
True
Enveloped viruses may enter their host cells by engulfment within coated vesicles (endocytosis).
True
Enveloped viruses may enter their host cells by fusion of their envelope with the cytoplasmic membrane, thereby depositing their nucleocapsid within the cell.
True
Gram staining divides bacterial species into two groups based on differences in cell wall structure.
True
Growth factors cannot be synthesized by the bacteria that use them and include amino acids, pyrimidines, and vitamins.
True
Immersion oil increases the amount of light entering the objective lens.
True
In order to stain flagella so that they may be readily observed by light microscopy, it is usually necessary to increase their thickness.
True
Invisible living creatures were thought to exist and cause disease long before they were ever observed.
True
It is possible to build a light microscope capable of 10,000x magnification, but the image would not be sharp because resolution is independent of magnification.
True
It was possible to view viruses only after the invention of the electron microscope because they are too small to be seen with a light microscope
True
John Tyndall demonstrated that microorganisms present in the air are carried on dust particles.
True
Light rays are refracted (bent) when they cross the interface between materials with different refractive indices.
True
Lysosomes maintain an acidic environment by actively pumping protons into their interior.
True
Methanogens may contribute to the greenhouse effect and global warming due to methane production.
True
Mordants increase the binding between a stain and specimen.
True
Negative staining with India ink can be used to reveal the presence of capsules that surround bacterial cells
True
Nitrogen can be obtained from either organic or inorganic sources.
True
One way in which small viruses package more information into a very small genome is to use overlapping genes so that the same base sequence is read in more than one reading frame.
True
Permease proteins that aid in the transport of nutrients resemble enzymes in their specificity for the substance to be transported. Each carrier is selective and will transport only a closely related set of substances.
True
Prions consist of proteins and have no apparent nucleic acid genome.
True
Prokaryotes were once described based on structures that were present in eukaryotes, but absent in prokaryotes.
True
Resolution improves when the wavelength of the illuminating light decreases.
True
Ribosomes are not considered to be organelles because they are not bounded by a membrane
True
Scanning electron microscopes bombard specimens with a stream of electrons; however, the specimen image is produce by electrons that are derived from atoms of the specimen itself rather than by the electrons used to bombard the specimen
True
Scanning tunneling electron microscopes create a three-dimensional image of specimens at atomic level resolution.
True
Some archaeal cells lack a cell wall.
True
Some archaeons are symbionts in animal digestive tracts.
True
Some microorganisms are useful in bioremediation processes that reduce the effects of pollution.
True
Some photosynthetic bacteria produce gas vacuoles that regulate their buoyancy but contain no lipid.
True
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
The DNA of some archaeons is stabilized with archaeal histone proteins forming particles resembling eukaryotic nucleosomes.
True
The endosymbiotic hypothesis is generally accepted as the origin of two eukaryotic organelles: mitochondria and chloroplasts
True
The extreme insolubility of ferric iron leaves little free iron available for transport into bacterial cells.
True
The first disease to be identified as being caused by a virus was tobacco mosaic disease
True
The largest of the viruses are similar in size to some small bacteria and are large enough to be seen with a light microscope.
True
The mechanism of pathogenesis by prions may involve a conformational change in the prion protein (PrP) to an abnormal form.
True
The most common capsid morphologies are icosahedral and helical.
True
The relationship between specific bacteria and specific diseases was first demonstrated by Koch
True
The trace amounts of micronutrients needed by microorganisms are usually supplied as inadvertent contaminants in water and regular media components.
True
Virus receptors are often not distributed uniformly over the surface of host cells, but are instead concentrated in lipid rafts.
True
Viruses in the extracellular state possess few, if any, active enzymes.
True
Viruses such as MS2 and Qß pack additional information into their genomes through the use of overlapping genes.
True
Which of the following is not true of viruses? A. Viruses are acellular. B. Viruses consist of one or more molecules of DNA or RNA enclosed in a coat of protein and sometimes in other more complex layers. C. Viruses can exist in two phases: intracellular and extracellular. D. Viruses replicate by binary fission.
Viruses replicate by binary fission
the ribosomal RNA studies that led to the division of prokaryotic organisms into the bacteria and archaea were begun by A. Pasteur. B. Woese. C. Needham. D. Watson.
Woese
32. A lysosome containing undigested material is called A. a phagosome. B. an endosome. C. a residual body. D. a coated vesicle.
a residual body.
the movement of molecules across a membrane from an area of lower concentration to higher concentration with the expenditure of energy is called A. facilitated diffusion. B. osmosis. C. passive diffusion. D. active transport.
active transport
which of the following processes can be used to bring nutrients into a cell against a concentration gradient? A. Active transport B. Facilitated diffusion C. Passive diffusion D. Active transport and facilitated diffusion
active transport
Nutrients can be concentrated from dilute solutions by A. pinocytosis. B. endocytosis. C. active transport and group translocation. D. electron transport.
active transport and group translocation
the cytoplasmic membrane of bacteria A. retains the cytoplasm and its contents., B. acts as a selectively permeable barrier, allowing some molecules to pass while preventing the movement of others., C. is the major site of ATP synthesis in aerobes. D. all of the above
all of the ABOVE
which of the following contribute to the environmental resistance of bacterial endospores A. Spore coat B. Low water content of endospore C. Presence of calcium dipicolinate D. Lower pH E. All of the choices are correct.
all of the above
which of the following is/are true of capsules A. They help bacteria escape phagocytosis by host cells., B. They retain water and help prevent desiccation of the bacteria., C. They prevent entry of many bacterial viruses.
all of the above
24. Microdomains in eukaryotic plasma membranes can participate in (three areas) A. cell movement. B. cell division. C. signal transduction. D. All of the choices are correct.
all of the choices are correct
44. Which of the following is a function of the mitochondrion? A. Tricarboxylic acid cycle enzyme reactions B. Electron transport C. ATP synthesis D. All of the choices are correct.
all of the choices are correct
the type 3 bacterial protein secretion machinery
all of the choices are correct
Lipids with polar and nonpolar ends are said to be A. amphipathic. B. amphibolic. C. bilateral. D. None of the choices are correct.
amphipathic
Export of flagellin subunits is mediated by A. an apparatus in the basal body of the flagellum that is related to the type II secretion pathway. B. the type I secretion pathway. C. an apparatus in the basal body of the flagellum that is related to the type III secretion pathway. D. None of the choices are correct.
an apparatus in the basal body of the flagellum that is related to the type III secretion
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 bacterium. B. an archaeon. C. a protozoan. D. a fungus.
an archaeon.
Prior to staining, smears of microorganisms are heat-fixed in order to A. allow eventual visualization of internal structures. B. ensure removal of dust particles from the slide surface. C. attach it firmly to the slide. D. create small pores in cells that facilitates binding of stain to cell structures.
attach it firmly to the slide
Old cultures of bacteria that have lost their ability to cause disease are said to be A. impotent. B. virulent. C. pathogenic. D. attenuated.
attenuated
rod shaped bacteria A. coccus. B. bacillus. C. vibrio. D. coccobacillus.
bacillus
The most important aspect of agar that makes it a useful ingredient for solidifying media for bacterial culture is
bacteria are unable to break it down so it stays solidified
49. Construction of flagella and/or cilia is directed by the A. axoneme. B. tubulin. C. centriole. D. basal body.
basal body.
Some complex viruses have icosahedral symmetry in the head region and helical symmetry in the tail. Overall, these viruses are said to have __________ symmetry.
binal
Confocal microscopes exhibit improved contrast and resolution by
blocking out stray light with an aperture located above the objective lens
which of the following is considered to be a differential staining procedure? A. Gram stain B. Acid-fast stain C. Both Gram stain and Acid-fast stain D. Leifson's flagella stain
both gram stain and acid fast stain
which of the following distinguish the field of microbiology from other fields of biology? A. The size of the organism studied. B. The techniques used to study organisms regardless of their size. C. Both the size of the organism studied and the techniques employed in the study of organisms. D. Neither the size of the organism studied nor the techniques employed in the study of organisms regardless of their size.
both the size of the organism studied and the techniques employed in the study of the organisms
Twitching or gliding motility involves A. type IV pili. B. axial fibrils. C. movement of slime. D. both type IV pili and movement of slime can be involved in twitching or gliding motility.
both type IV pili and movement of slime can be involved in twitching or gliding motility.
Sortase is a protein enzyme of bacteria that
catalyzes covalent attachment of some surface proteins to peptidoglycan.
45. The organelle responsible for harvesting light as an energy source for photosynthesis is the A. kinetoplast. B. centriole. C. chloroplast. D. mitochondrion.
chloroplast
29. The endoplasmic reticulum is composed of flattened sacs called A. thylakoids. B. cristae. C. cisternae. D. vacuomes.
cisternae
The term used to describe bacteria that are intermediate in shape between spherical and rod-shaped is A. cocci. B. bacilli. C. vibrio. D. coccobacilli.
coccobacilli
spherical shaped bacteria A. coccus. B. bacillus. C. vibrio. D. coccobacillus.
coccus
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 bilayer with embedded proteins. C. contain sterols such as cholesterol. D. consist of a lipid monolayer.
consist of a lipid monolayer
in the gram staining procedure, the primary stain is A. iodine. B. safranin. C. crystal violet. D. alcohol.
crystal violet
25. The liquid component of the cytoplasm is known as the A. thylakoid. B. cytosol. C. cytoskeleton. D. stroma.
cytosol
the instrument that produces a bright image against a dark background is called a ___________ microscope A. phase-contrast B. electron C. bright-field D. dark-field
dark-field
38. Receptor mediated endocytosis A. depends on formation of clathrin coated pits that pinch off. B. is used to internalize molecules such as hormones, growth factors, iron, and cholesterol. C. involves formation of caveolae that are enriched in cholesterol and caveolin. D. is typically used to internalize plasma membranes added by exocytosis. E. depends on formation of clathrin coated pits that pinch off and is used to internalize molecules such as hormones, growth factors, iron, and cholesterol.
depends on formation of clathrin coated pits that pinch off is used to internalize molecules such as hormones, growth factors, iron, and cholesterol.
40. Stacks of cisternae in the Golgi apparatus are referred to as
dictyosomes
The gram-staining procedure is an example of A. simple staining B. negative staining C. differential staining D. fluorescent staining
differential staining
The cell membranes of wall-less archaeons are strengthened by A. diglycerol ethers. B. glycoprotein or protein layers. C. pseudomurein. D. diglycerol tetraethers.
diglycerol tetraethers
Atomic force microscopes use a scanning probe that maintains a fixed distance from the surface of the specimen. It is useful for specimens that A. do not conduct electricity well. B. have extremely uneven surfaces. C. both do not conduct electricity well and have extremely uneven surfaces are correct. D. neither do not conduct electricity well nor have extremely uneven surfaces is correct.
do not conduct electricity well
A new microbe has been discovered in the rumen of sheep. Microscopy shows no evidence of a nuclear membrane and biochemical studies of the cell wall demonstrate the lack of peptidoglycan. Metabolic studies show that this microbe generates methane. This microbe would most likely be classified in the: A. Domain Bacteria B. Domain Archaea C. Domain Eukarya, Kingdom Fungi D. Domain Eukarya, Protists
domain archaea
Prions are of significance because they cause infections of A. domestic animals and humans. B. plants. C. fungi. D. prokaryotes.
domestic animals and humans
Human cancer causing viruses most often have a ___________ genome.
dsDNA
The nucleic acids carried by viruses usually consist of A. DNA. B. RNA. C. either DNA or RNA. D. both DNA and RNA simultaneously.
either DNA or RNA.
Nonenveloped viruses most often gain access to eukaryotic host cells by A. fusion with the host cell plasma membrane followed by entrance of the nucleocapsid into the cytoplasm. B. endocytosis. C. pinocytosis. D. nucleic acid injection through the plasma membrane.
endocytosis
36. The major site of cell membrane synthesis is the A. nucleus. B. plasma membrane. C. lysosome. D. endoplasmic reticulum.
endoplasmic reticulum.
which bacterial structure may survive if temperatures applied during food preservation processes are too low? A. Flagella B. Endospores C. Plasma membranes D. Ribosomes
endospores
the lipopolysaccharide that is found in the outer membrane of gram-negative bacteria is also known as A. exotoxin. B. teichoic acid. C. murein. D. endotoxin.
endotoxin
ether vs ester
ester has a double bond on the adjacent carbon triglycerides are ester bonds
Cells with a relatively complex morphology that have a true membrane-delimited nucleus are called A. prokaryotes. B. eukaryotes. C. urkaryotes. D. nokaryotes.
eukaryotes
scientists study microorganisms on earth today to search for life forms elsewhere, as well as to explore the origins of life on earth. these microorganisms that are studied are referred to as A. Existing B. extant. C. extinct. D. extirpated.
extant
movement of molecules from an area of high concentration to an area of low concentration with the use of a carrier molecule A. facilitated diffusion. B. osmosis. C. passive diffusion. D. active transport.
facilitated diffusion
Glycoprotein spikes protruding from the outer surface of viral envelopes function as A. toxins. B. factors that bind to host cells. C. cell lysis factors. D. factors needed for site specific recombination.
factors that bind to host cells
The usefulness of agar in solidifying microbiological growth media is limited because it does not remain solid at temperatures about 28oC.
false
Viruses are not generally studied by microbiologists because they are not classified as living organisms
false
Protists contain all of the following forms of life except A. protozoa. B. fungi. C. slime molds. D. algae.
fungi
The concept that human and animal diseases are caused by microorganisms is called the the A. cell theory. B. germ theory. C. causative theory. D. disease theory.
germ theory
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. facillitated diffusion B. micronutrient regulator C. passive diffusion D. group translocation
group translocation
External structures that are found in Archaea but not Bacteria are A. pili B. flagella C. hami D. peptidoglycan
hami
Studies by Emil von Behring and Shibasaburo Kitasoto demonstrated that inactivated toxins can induce the synthesis of antitoxins in the blood of rabbits. These antitoxins are the basis of: a. humoral immunity b. cell-mediated immunity c. antibiotic immunity d. phagocyte-mediated immunity
humoral immunity
Two major types of symmetry found in viruses include
icosahedral and helical.
Poliovirus receptors are found
in nasopharynx, gut, and spinal cord anterior horn cells.
In eukaryotic cells, the enzymes involved in the tricarboxylic acid cycle (Kreb's cycle) are located A. in the cytoplasm. B. in the outer mitochondrial membrane. C. in the inner mitochondrial membrane. D. in the matrix of the mitochondria. E. in the cristae.
in the matrix of the mitochondria.
which of the following is not part of the process by which an endospore transforms to become a vegetative cell? A. Germination B. Activation C. Induction D. Outgrowth
induction
All of the following are methods of prion disease transmission EXCEPT
inhalation (airborne).
proteins that are embedded within the cytoplasmic membrane and not easily extracted are called ______ proteins A. peripheral B. integral C. external D. internal
integral
A new protein has been described that transports a growth factor across the plasma membrane. This protein is most likely a/an: A. peripheral membrane protein, facing outward. B. peripheral membrane protein, facing the cytoplasmic side. C. integral membrane protein. D. cytoplasmic protein.
integral membrane protein
27. Protein filaments with a diameter of about 10 nm that are major components of the cytoskeleton are called A. microtubules. B. microfilaments. C. intermediate filaments. D. mycelia.
intermediate filaments.
Many of the enzymes found in virus particles are A. required for viral attachment to host cells. B. involved in viral entry into host cells. C. involved in the replication of viral nucleic acid. D. All of the choices are correct.
involved in the replication of viral nucleic acid.
as the resolution of a microscope system improves, the size of the smallest object that can be seen clearly A. is larger. B. is smaller. C. is not affected.
is smaller
Although penicillin inhibits peptidoglycan synthesis, bacterial cells will continue to grow normally in the presence of penicillin in a(n)______environment. a. hypotonic b. isotonic c. hypertonic d. nonpolar
isotonic
all of the following statements about the periplasmic space are true except: A. It is found only in gram-positive bacteria. B. It is located between the plasma membrane and outer membrane of gram-negative bacteria. C. It contains hydrolytic enzymes and binding proteins involved in nutrient acquisition. D. All of the choices are true.
it is found only in gram positive bacteria
who is credited with developing and documenting the first vaccination procedure against smallpox A. Koch B. Pasteur C. Jenner D. Lister
jenner
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. Koch C. Pasteur D. Lister
koch
Archaeal cell walls A. are disrupted by treatment with lysozyme or penicillin. B. are similar to those of gram-negative bacteria. C. lack murein and D-amino acids. D. include orthomureine.
lack murein and D-amino acids.
Acid-fast organisms such as Mycobacterium tuberculosis resist decolorization by an acid -alcohol wash because of the high concentration of _____ in their cell walls. a. proteins b. carbohydrates c. lipids d. peptidoglycan
lipids
Ether-linked lipid
lipids are less resistant to hydrolysis, potentially because of the way the acyl chain is linked to the glycerol backbone
Diphtheria toxin is produced only by strains of Corynebacterium diphtheriae that are infected with a particular bacteriophage. This is an example of
lysogenic conversion
The production of cholera toxin by virulent strains of Vibrio cholera is dependent upon genes in a bacteriophage. This is an example of
lysogenic conversion
34. Enzymes needed to digest all types of macromolecules are found in A. lysosomes. B. Golgi apparatus. C. mitochondria. D. centrioles.
lysosomes
The food vacuoles and phagocytic vacuoles are most similar to A. mitochondria. B. chloroplasts. C. lysosomes. D. Golgi apparatus.
lysosomes.
which of the following is not considered a micronutrient?
magnesium
28. A filamentous organelle comprised of tubulins with a diameter of 25 nm is called A. microtubule. B. microfilament. C. intermediate filament. D. mycelia.
microtubule.
a specimen has been prepared for viewing with a transmission electron microscope, using uranyl acetate as a negative stain. the area stained by the uranyl acetate will be ________ electron dense compared to specimen itself A. more B. less C. equally
more
Regions of a specimen with higher electron density scatter ___________ electrons and, therefore, appear __________ in the image projected onto the screen of a transmission electron microscope. A. more; lighter B. more; darker C. fewer; darker D. fewer; lighter
more; darker
chemotaxis is a process by which bacteria A. move toward an attractant or away from a repellent. B. avoid phagocytosis. C. respond metabolically to the presence of autoinducer molecules. D. move on solid surfaces by means of type IV fimbriae.
move toward an attractant or away from a repellent.
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 A. capsid. B. nucleocapsid. C. matrix. D. virion.
nucleocapsid
Genes whose expression (or abnormal expression) causes cancer are called A. cancer genes. B. progenes. C. oncogenes. D. carcinogens.
oncogenes.
22. Membrane delimited intracellular structures that perform specific functions in cells are A. organelles. B. organs. C. tissues. D. systomis.
organelles
Who of the following provided the evidence needed to discredit the concept of spontaneous generation? A. Pasteur B. Koch C. Semmelweiss D. Lister
pasteur
who is credited with developing a vaccine against chicken cholera A. Koch B. Pasteur C. Jenner D. Lister
pasteur
23. The plasma membrane of eukaryotes contains all of the following EXCEPT A. phosphoglycerides. B. sphingolipids. C. sterols. D. peptidoglycan.
peptidoglycan
which of the following protects bacteria from lysis in dilute solutions and helps to determine their cellular morphology or shape? A. Plasma membrane B. Peptidoglycan C. Capsule D. Gas vacuoles
peptidoglycan
proteins that are loosely associated with the cytoplasmic membrane are called _______ proteins A. peripheral B. integral C. external D. internal
peripheral
51. Flimmer filaments A. permit flagella to pull rather than push the cell. B. function to move cells on solid surfaces. C. are components of all eukaryotic flagella. D. None of the choices are correct.
permit flagella to pull rather than push the cell.
30. The process by which a cell imports large particles by enclosing them in vesicles pinched off from the plasma membrane is called A. exocytosis. B. phagocytosis. C. pinocytosis. D. nutrient cytosis.
phagocytosis
an instrument that magnifies slight differences in the refractive index of cell structures is called a ___________ microscope A. phase-contrast B. electron C. fluorescence D. densitometric
phase-contrast
If the decolorizer is left on too long in the Gram-staining procedure, gram-positive organisms will be stained __________ and gram-negative organisms will be stained
pink; pink
Viroids are of economic significance because they cause disease in A. plants. B. animals. C. humans. D. All of the choices are correct.
plants
A ________ assay is most useful for determining the viability of a viral preparation. A. direct (electron microscopic) count B. hemagglutination C. plaque D. PCR
plaque
Most enveloped viruses use the host __________ membrane as their envelope source. A. plasma B. nuclear C. mitochondrial D. none of these
plasma
Shrinkage of the plasma membrane away from the cell wall when the bacterium is placed in a hypertonic environment is called A. osmolysis. B. plasmolysis. C. hydrolysis. D. hypertonolysis.
plasmolysis
bacterial cells that are variable in shape are called A. vibrio. B. pleomorphic. C. coccobacilli. D. hyphal.
pleomorphic
Cells with a relatively simple cell morphology that do not have a true membrane-delimited nucleus are called A. prokaryotes. B. eukaryotes. C. urkaryotes. D. nokaryotes.
prokaryotes
The function of the viral protein coat is to A. protect the viral genetic material. B. aid in the transfer of the viral genetic material between host cells. C. elicit the production of protective antibodies. D. protect the viral genetic material and aid in the transfer of the viral genetic material between host cells.
protect the viral genetic material and aid in the transfer of the viral genetic material between host cells.
RNA serves to convert the information stored in DNA to ________. A. carbohydrates B. protein C. lipids D. RNA
protein
All of the following processes are located within a membranous structure EXCEPT A. cell respiration - electron transport chain. B. photosynthesis - light reactions. C. intracellular digestion of food particles. D. protein synthesis (translation).
protein synthesis (translation)
The power used by most bacterial flagellar motors is produced by A. synthesis of glucose. B. ATP hydrolysis. C. proton motive force (PMF). D. All of the choices are correct.
proton motive force
A newly discovered unicellular microbe has a nucleus containing linear chromosomes and surrounded by a membrane. It has mitochondria, 80s ribosomes, and is covered by cilia. There is no cell wall external to the plasma membrane. This organism most likely would be a/an A. bacterium. B. archaeon. C. protozoan. D. fungus. E. algae.
protozoan.
After the decolorizer has been added, gram-positive organisms are stained __________ and gram-negative organisms are stained __________.
purple; colorless
After the secondary stain has been added, gram-positive organisms are stained __________ and gram-negative organisms are stained __________.
purple; pink
After the primary stain has been added but before the decolorizer has been used, gram-positive organisms are stained __________ and gram-negative organisms are stained __________.
purple; purple
If the decolorizer is not left on long enough in the Gram-staining procedure, gram-positive organisms will be stained __________ and gram-negative organisms will be stained
purple; purple
Immersion oil can be used to increase the resolution achieved with some microscope lenses because it increases the __________ between the specimen and the objective lens. A. optical density B. refractive index C. optical density and refractive index D. neither optical density nor refractive index
refractive index
Endocytic events A. add membrane to the cell surface. B. remove membrane from the cell surface. C. have no effect on the plasma membrane.
remove membrane from the cell surface
35. Proteins are synthesized on structures called A. mesosomes. B. lysosomes. C. ribosomes. D. chromosomes.
ribosomes
each of the following provides evidence in support of the primary role of RNA in the evolution of life except: A. Some RNA molecules are catalytic. B. RNA catalyzes peptide bond formation during protein synthesis. C. ATP (energy currency of the cell) is a ribonucleotide. D. RNA is less chemically stable than DNA. E. RNA can regulate gene expression.
rna is less chemically stable than dna
which of the following is a characteristic of active transport? A. Saturable uptake rate B. Use of ATP or a proton gradient as a source of metabolic energy C. Can move materials against a concentration gradient D. All of the choices are correct.
saturable uptake rate, use of ATP or proton motive force as a source of metabolic energy, and can move materials against a concentration gradient (ALL OF THE ABOVE)
which type of microscopy would be preferred for creating a three dimensional view of the distribution and arrangement of flagella on a bacterial cell surface? A. Bright-field microscopy B. Scanning electron microscopy C. Fluorescence microscopy D. Transmission electron microscopy
scanning electron microscopy
A __________ genome exists as several separate, nonidentical molecules that may be packaged together or separately. A. diploid B. segmented C. polyploid D. fractionated
segmented
__________ membranes allow some molecules to pass but not others. A. Permeable B. Inverted monolayer C. Selectively permeable D. Impermeable
selectively permeable
Viral capsids are generally constructed without any outside aid once the subunits have been synthesized. This process is called A. facilitated assembly. B. self-assembly. C. spontaneous maturation. D. self-maturation.
self-assembly.
which of the processes named here is the least likely to contribute to the evolution of genetic diversity of bacteria and archaea A. Mutation B. Sexual reproduction C. Binary fission D. Horizontal gene transfer
sexual reproduction
Viroids are: A. proteins that may infect man and other animals causing spongiform encephalopathy. B. a class of so-called slow viruses. C. a new class of small single stranded DNA viruses that infect some animals. D. short infectious single stranded RNAs that can infect some plants.
short infectious single stranded RNAs that can infect some plants.
Rigid bacteria with a helical cell shape are called A. vibrios. B. spirilla. C. spirochetes. D. coccobacilli.
spirilla
Flexible bacteria with a helical shape are called: a. vibrios b. spirilla c. spirochetes d. coccobacilli
spirochetes
The concept that living organisms arise from nonliving material is called A. biogenesis. B. cell theory. C. spontaneous generation. D. germ theory.
spontaneous generation
47. The formation of carbohydrate (CO2 fixation) in the dark reaction of photosynthesis, takes place in the A. stroma. B. cytoplasm. C. thylakoid membrane. D. nucleus.
stroma
scanning electron microscopy is most often used to reveal A. surface structures. B. internal structures. C. both surface and internal structures simultaneously. D. either surface or internal structures, but not simultaneously.
surface structures
Square planar arrangement of cells that forms when round bacteria remain attached to each other during reproduction are called A. streptococci. B. staphylococci. C. tetrads. D. sarcinae.
tetrads
motile bacteria have been placed in an environment with a gradient of a chemical attractant. which of the following behaviors would u predict? A. Bacteria will randomly switch back and forth between runs and tumbles. B. The bacteria will only exhibit runs away from the chemical. C. The bacteria will reduce tumbling frequency. D. The bacteria will reduce run duration in the direction of the chemical. E. The bacteria will both reduce tumbling frequency and increase run duration in the direction of the chemical.
the bacteria will both reduce tumbling frequency and increase run duration in the direction of the chemical
Hemagglutination is A. the clumping together of red blood cells in the presence of a viral suspension. B. the binding of iron in the process of a viral suspension. C. the clumping together of infected cells in the presence of a viral suspension. D. None of the choices are correct.
the clumping together of red blood cells in the presence of a viral suspension.
The most important distinguishing feature of eukaryotes that is lacking in prokaryotes is A. the presence of a cell wall in eukaryotes. B. the cell respiration process which if fundamentally different in prokaryotes. C. the DNA replication mechanism D. the division of the cell into compartments bounded by membranes.
the division of the cell into compartments bounded by membranes
a pathogenic bacteria species has mutated and is no longer able to synthesize a capsule. what outcome would u predict? A. The mutated bacteria will be more virulent. B. The mutated bacteria will not be able to cause disease as readily. C. The mutated bacteria will be protected from plasmolysis in hypertonic environments. D. The mutated bacteria will undergo osmotic lysis in hypotonic environments.
the mutated bacteria will not be able to cause disease as readily
Predict how the plasma membrane fatty acid composition would change as the temperature of the habitat of an aquatic bacterial species warms from 2 C to 15 C during the spring and summer months A. The percentage of saturated fatty acids would increase. B. The percentage of unsaturated fatty acids would increase. C. The percentage of saturated fatty acids would decrease. D. The percentage of saturated fatty acids would remain unchanged.
the percentage of saturated fatty acids would increase
if you forgot to heat fix a smear before doing a gram stain, which of the following might occur A. The stains would not adhere to the bacteria. B. The smear may not adhere to the slide. C. The decolorization step of the Gram stain would not work properly. D. Gram-positive and Gram-negative bacteria would both stain purple.
the smear may not adhere to the slide
which of the following is not true of bacterial plasmids? A. They can replicate independently of the chromosome. B. They may carry genes for drug resistance. C. They are required for host growth and/or reproduction. D. They may carry genes that enhance survival of the bacterium under certain conditions.
they are required for host growth and/or reproduction
Endospores represent a challenge to the fields of industrial and medical microbiology because: a. spore forming organisms are often dangerous pathogens b. spores are significantly smaller than vegetative cells c. they are resistant to harsh enviornments, thus allowing survival of spore forming organisms under conditions in which nonsporulating cells would not survive and spore forming organisms are often dangerous pathogens are correct.
they are resistant to harsh enviornments, thus allowing survival of spore forming organisms under conditions in which nonsporulating cells would not survive and spore forming organisms are often dangerous pathogens are correct.
48. The light reactions of photosynthesis, which form ATP and NADPH, take place in the A. stroma. B. cytoplasm. C. thylakoid membrane. D. nucleus.
thylakoid membrane.
which type of microscopy would be preferred for showing fine internal detail of the eukaryotic organelles? A. Bright-field microscopy B. Scanning electron microscopy C. Fluorescence microscopy D. Transmission electron microscopy
transmission electron microscopy
11. Chloroplasts are the site for both the light and dark reactions of photosynthesis.
true
12. The majority of mitochondrial proteins are manufactured under the direction of the nuclear DNA by cytoplasmic ribosomes.
true
21. Eukaryotes usually have more than one chromosome for the storage of genetic information.
true
All eukaryotes have a membrane delimited nucleus
true
Charles Chamberland developed porcelain filters that allowed other scientists to demonstrate that viruses are smaller than bacteria.
true
Fanny Hesse first suggested that agar be used to solidify microbiological media.
true
M. J. Berkeley demonstrated that the great potato blight of Ireland was caused by a fungus.
true
Many archaeal genomes include chromosomes and plasmids a. true b. false
true
Whose work on spontaneous generation first demonstrated the existence of a very heat-resistant form of bacteria that are called endospores? A. Schwann B. Redi C. Tyndall D. Pasteur
tyndall
Who of the following was the first to observe and accurately describe microorganisms? A. Pasteur B. Lister C. van Leeuwenhoek D. Tyndall
van Leeuwenhoek
the term used to describe bacteria that are shaped like curved rods is A. coccus. B. bacillus. C. vibrio. D. coccobacillus.
vibrio
A complete virus particle is called a A. capsid. B. nucleocapsid. C. virion. D. cell.
virion.
Which type of phage always lyses its host cell? A. Temperate B. Virulent C. Lysogenic D. Prophage
virulent
which of the following provides the best explanation for why viruses are not included in the three domain system? A. Viruses are too small. B. Viruses have either DNA or RNA, not both. C. Viruses are not a cellular life form. D. Viruses show no evidence of evolution.
viruses are not a cellular life form
A wide variety of microorganisms are commercially used to manufacture _________ for human consumption. A. vitamins B. sugars C. fatty acids D. none of the choices
vitamins