Exam 1
Gram-positive bacteria have a thinner layer of peptidoglycan than gram-negative bacteria. True or False
false
Like prokaryotic cells, most eukaryotic cells have an external cell wall. True or False
false
Unlike members of the Bacteria, most archaeans have linear chromosomes. True or False
false
A purine or pyrimidine that is attached to a sugar, either ribose or deoxyribose, which is attached to one or more phosphate groups is called a _______. nucleic acid nucleoside nitrogenous base nucleotide
d
Enzymes needed to digest all types of macromolecules are found in mitochondria. centrioles. Golgi apparatus. lysosomes.
d
Most bacterial and archaeal cells divide by Multiple Choice All of the choices are correct. mitosis. meiosis. binary fission.
d
Organisms that are not drastically affected by increased pressure are called Multiple Choice barophilic. osmophilic. osmotolerant. barotolerant.
d
Proteins are synthesized on structures called Multiple Choice mesosomes. chromosomes. lysosomes. ribosomes.
d
Proteins that are loosely associated with the cytoplasmic membrane are called __________ proteins. Multiple Choice integral external internal peripheral
d
The liquid component of the cytoplasm is known as the Multiple Choice cytoskeleton. stroma. thylakoid. cytosol.
d
Bacterial peptidoglycan is not a good target for antibiotics because it is present in human cells as well, leading to host damage. True or False
false
A filamentous organelle comprised of tubulins with a diameter of 25 nm is called microfilament. mycelia. intermediate filament. microtubule.
d
in order to stain flagella so that they may be readily observed by light microscopy, it is usually necessary to increase their thickness. True or False
truw
Gram-positive bacteria have a structurally and chemically more complex cell wall than gram-negative bacteria. True or False
False
Pasteurization is used to Multiple Choice kill any pathogens present and retard spoilage. sterilize beverages. retard spoilage. kill any pathogens present.
A
Which is not true of viruses? Multiple Choice They infect animal and plant cells only. They can be observed with an electron microscope. They replicate only inside host cells. They can exist in an intracellular or extracellular phase. They are acellular.
A
Which of the following is NOT true regarding ATP synthases? Multiple Choice The proton flow is outward during ATP synthesis. They require proton motive force to make ATP. The subunits of ATP synthase undergo conformational changes during ATP production. Incorrect They span the inner membrane of mitochondria.
A
Which of the following is a useful mechanism of action for an antibacterial drug? Multiple Choice All of the choices are correct. Inhibition of cell wall synthesis Interference with RNA and DNA synthesis Inhibition of protein synthesis
A
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? Multiple Choice Lister Pasteur Koch Fracastoro
C
A pathogenic bacterial species has mutated and is no longer able to synthesize a capsule. Which outcome would you predict? Multiple Choice The mutated bacteria will not be able to cause disease as readily. The mutated bacteria will be more virulent. The mutated bacteria will be protected from plasmolysis in hypertonic environments. The mutated bacteria will undergo osmotic lysis in hypotonic environments.
a
Antiseptic surgery was pioneered by Multiple Choice Lister. Pasteur. Jenner. Kitasato.
a
Each of the following provides evidence in support of the primary role of RNA in the evolution of life EXCEPT: Multiple Choice RNA is less chemically stable than DNA. ATP (energy currency of the cell) is a ribonucleotide. RNA can regulate gene expression. RNA catalyzes peptide bond formation during protein synthesis. Some RNA molecules are catalytic.
a
Moist heat sterilizes by Multiple Choice denaturing proteins. causing production of singlet oxygen. All of the choices are correct. causing the formation of thymine dimers.
a
Photoautotrophs use light energy directly for Multiple Choice the production of ATP and NADPH. the reduction of carbon dioxide to glucose. neither the production of ATP and NADPH nor the reduction of carbon dioxide to glucose. both the production of ATP and NADPH and the reduction of carbon dioxide to glucose.
a
The disinfectant of choice for municipal water supplies is __________. Multiple Choice chlorine ultraviolet light fluorine either fluorine or chlorine
a
The most specific term usually used to describe a substance in a biological system that increases the rate of a reaction without being permanently changed by the reaction is a(n) Multiple Choice enzyme. catalyst. Incorrect rate increaser. catalyzer.
a
The plasma membrane of eukaryotes contains all of the following EXCEPT Multiple Choice peptidoglycan. sphingolipids. sterols. phosphoglycerides.
a
The synthesis of glucose from non-carbohydrate precursors is called ______. Multiple Choice gluconeogenesis None of the choices are correct. glycolysis glutamine synthase
a
The term used to describe bacteria that are rod-shaped is Multiple Choice bacillus. vibrio. coccus. coccobacillus.
a
When the end product of a pathway inhibits catalysis of the first step of that pathway, this phenomenon is called Multiple Choice feedback inhibition. non-competitive inhibition. metabolic channeling. reversible covalent modification.
a
Which of the following is useful in distinguishing between prokaryotic and eukaryotic cells? Multiple Choice The presence of membrane-delimited organelles within the cytoplasm All of the choices are correct. The presence of ribosomes for the synthesis of proteins The use of DNA for the storage of genetic information
a
An chemical reaction that requires an input of energy in order to proceed is __________. Multiple Choice None of the choices are correct. endergonic impossible exergonic
b
As the magnification of a series of objective lenses increases, the working distance Multiple Choice cannot be predicted. decreases. increases. stays the same.
b
Development of drug resistance is encouraged by Multiple Choice using drugs appropriate for the infectious agent being treated . widespread use of broad-spectrum drugs. avoidance of indiscriminate use of drugs. use of two drugs simultaneously with the hope that each will prevent the emergence of resistance to the other. use of a high enough concentration of the drug to destroy any spontaneous resistant mutants that might arise.
b
Old cultures of bacteria that have lost their ability to cause disease are said to be Multiple Choice pathogenic. attenuated. virulent. impotent.
b
Prions are of significance because they cause infections of Multiple Choice prokaryotes. domestic animals and humans. fungi. plants.
b
The Archaea generally lack which of the following that are normally found in gram-negative bacteria? Multiple Choice Outer membrane All of the choices are correct. Lipopolysaccharide A complex peptidoglycan network
b
The most important distinguishing feature of eukaryotes that is lacking in prokaryotes is Multiple Choice the presence of a cell wall in eukaryotes. the division of the cell into compartments bounded by membranes. the cell respiration process which if fundamentally different in prokaryotes. the DNA replication mechanism .
b
The reduction of atmospheric nitrogen to ammonia is called _______. Multiple Choice denitrification nitrogen fixation nitrification ammonification
b
The terms phototroph and chemotroph refer to an organism's source of Multiple Choice electrons. energy. carbon. nitrogen.
b
Which of the following is/are true about enzymes? Enzymes are highly specific for the substrates they react with and catalyze only one or a limited set of possible reactions with those substrates. All of the choices are correct. Enzymes are catalysts that speed up reactions. Enzymes are proteins that can be denatured by changes in pH or temperature.
b
Who of the following was the first to observe and accurately describe microorganisms? Multiple Choice Pasteur van Leeuwenhoek Lister Tyndall
b
All of the following are reasons why some scientists believe that the term "prokaryote" is a somewhat artificial designation and should be discarded except Multiple Choice Some bacteria have internal membranous structures. Incorrect Many bacterial have cytoskeletal elements. Some bacteria have 80S ribosomes. Some bacteria have their genetic material enclosed within a membrane.
c
All of the following processes are located within a membranous structure EXCEPT Multiple Choice photosynthesis - light reactions. intracellular digestion of food particles. protein synthesis (translation). cell respiration - electron transport chain.
c
Cells carry out three major types of work; which of the following involves energy for cell motility and the movement of structures within cells? Multiple Choice None of the choices are correct. Transport work Mechanical work Chemical work
c
Cells carry out three major types of work; which of the following involves the synthesis of macromolecules as well as the breakdown of substances for their energy? Multiple Choice Transport work None of the choices are correct. Chemical work Mechanical work
c
Cells with a relatively simple cell morphology that do not have a true membrane-delimited nucleus are called Multiple Choice eukaryotes. nokaryotes prokaryotes urkaryotes.
c
Consider a biochemical pathway with five steps that lead to the production of product Q. If there is an abundance of product Q, the most efficient way to slow down the entire pathway would be to regulate _____________________. Multiple Choice the last enzyme in the pathway every enzyme in the pathway the first enzyme in the pathway
c
Quorum sensing Multiple Choice plays an important role in formation of biofilms by Pseudomonas aeruginosa. is a phenomenon in which bacteria monitor their own population density. All of the choices are correct. depends on the sensing of signal protein molecules.
c
Sterilization involves __________ all viable microorganisms. Multiple Choice removing killing Incorrect killing OR removing metabolically inactivating
c
Synthesis of complex molecules from simpler ones with the input of energy is called ______. Multiple Choice catabolism amphibolism anabolism metabolism
c
The process by which a cell imports large particles by enclosing them in vesicles pinched off from the plasma membrane is called nutrient cytosis. pinocytosis. phagocytosis. Correct exocytosis.
c
The simplest viruses consist of Multiple Choice Protein only. RNA, DNA and enzymes in a protein coat with a lipid envelope. RNA or DNA in a protein coat. RNA or DNA in a protein coat covered with lipid envelope. RNA only.
c
The term used to describe bacteria that are shaped like curved rods is Multiple Choice coccus. bacillus. vibrio. coccobacillus.
c
What is the most compelling reason why DNA, rather than RNA, evolved to be the storage repository for genetic information in cellular life forms? Multiple Choice DNA has deoxyribose rather than ribose. DNA is double-stranded rather than single-stranded. DNA molecules are more chemically stable than RNA molecules.
c
Where is the electron transport chain located in bacterial cells? Multiple Choice Mitochondrial inner membrane Mitochondrial outer membrane Plasma membrane Periplasm
c
Which group of microbes contains organisms necessary for production of wine and bread? Multiple Choice Bacteria Archaea Fungi Algae
c
Which kind of sterilization procedure takes advantage of the size of microorganisms? Multiple Choice Autoclaving Open flame Filtration Use of chemicals
c
Who is usually credited with the discovery of penicillin? Duchesne Ehrlich Fleming Florey and Chain
c
The most selective antibacterial agents are those that interfere with bacterial cell wall synthesis. This is because Multiple Choice eukaryotic cells do not take up the drugs. bacterial cell wall synthesis is easily inhibited whereas eukaryotic cell wall synthesis is more resistant to the actions of the drugs. eukaryotic cells inactivate the drugs before they can do any damage. bacterial cell walls have a unique structure not found in eukaryotic host cells.
d
The ribosomal RNA studies that led to the division of prokaryotic organisms into the Bacteria and the Archaea were begun by Multiple Choice Pasteur. Needham. Watson. Woese.
d
Which of the following diseases is (are) caused by prions? Multiple Choice Scrapie Kuru and Creutzfeldt-Jakob Disease Mad cow disease All of the choices are ciorect
d
Which of the following is true about membrane filters? Multiple Choice It can be used only to remove organisms from liquids. It does not truly sterilize because it removes rather than kills microorganisms. It can be used only to remove organisms from liquids and it does not truly sterilize because it removes rather than kills microorganisms. It can't be depended on to remove all viruses from liquids.
d
You are studying a newly discovered prokaryotic microorganism and are attempting to determine whether it will be classified in the domain Bacteria or in the domain Archaea. All of the following would be helpful in making that distinction except Multiple Choice Type of membrane lipids Sequence of small subunit ribosomal RNA Presence or absence of peptidoglycan in cell walls Presence or absence of double-stranded circular DNA genome
d
Archaeal and Bacterial pili are identical in structure and function. True or False
false
All of the following are methods of prion disease transmission EXCEPT Multiple Choice inheritance (genetic). Incorrect contamination through use of inadequately processed surgical instruments. organ or tissue transplantation. inhalation (airborne). ingestion of infected tissue.
inhalation
Prokaryotes were once described based on structures that were present in eukaryotes, but absent in prokaryotes. True or False
treu
Many archaeal genomes include chromosomes and plasmids. True or False
true
Many enzyme catalyzed reactions are freely reversible; however, some key steps require separate enzymes for the reverse step in order to provide for independent regulation of anabolic and catabolic pathways. True or False
true
Mordants increase the binding between a stain and specimen. True or False
true
Nongrowing cells continuously degrade and resynthesize cellular molecules during a process known as cellular turnover. True or False
true
The endosymbiotic hypothesis is generally accepted as the origin of two eukaryotic organelles: mitochondria and chloroplasts. True or False
true