Microbiology Exam 1

Which of the following is a correct statement about bacterial cell walls? a. All bacterial cell walls contain peptidoglycan. b. All bacterial species have cell walls. c. All bacterial cell walls contain hydrophobic and hydrophilic regions. d. All bacterial cell walls can be characterized as either Gram-Negative or Gram-positive.

All bacterial cell walls contain peptidoglycan

Adding salt or sugar to food is a great way to preserve these foods for a longer period of time and prevent bacterial spoilage. Why? a. Adding sugar or salt creates a hypertonic environment and water will be lost from bacterial cells, leading to lysis of the cell. b. Adding sugar or salt creates a hypertonic environment and water will be lost from bacterial cells, leading to plasmolysis. c. Adding sugar or salt creates a hypotonic environment and water will be gained by the bacterial cell. d. Adding sugar or salt creates an isotonic environment and water will be lost from the bacterial cell.

Adding sugar or salt creates a hypertonic environment and water will be lost from bacterial cells, leading to plasmolysis.

Which of the following is an incorrect statement about biofilms? a. Biofilms are sticky communities made up of single or diverse species. b. Biofilms can develop on nearly any surface. c. Biofilms are composed of planktonic bacteria. d. An estimated 60 to 80% of infectious diseases in humans are due to biofilm-creating microbes.

Biofilms are composed of planktonic bacteria

Which of the following is an incorrect statement about prokaryotes? a. All prokaryotes have a simpler genetic makeup that eukaryotic cells. b. All prokaryotes are unicellular. c. Both prokaryotic domains include known human pathogens. d. All prokaryotes lack a membrane-bound nucleus.

Both prokaryotic domains include known human pathogens.

Which of the following is a molecule? a. 3He2+ b. 123l c. Ca+2 d. C6H12O6

C6H12O6

Which of the following is an organic molecule? a. NaCl b. CH4 c. CO2 d. H2O

CH4

Penicillin is an antibiotic that interferes with peptidoglycan construction in cell walls. Why would this antibiotic not be a good treatment option for patients infected with Mycoplasma pneumonia? a. The cell wall of the organism Mycoplasma pneumonia contains pseudomurein instead of peptidoglycan. b. The organism Mycoplasma pneumonia does not have a cell wall. c. Mycoplasma pneumonia is a virus and therefore antibiotics do not have a target. d. Mycoplasma pneumonia is a Gram-positive organism and therefore penicillin would be an excellent treatment of choice.

The organism Mycoplasma pneumonia does not have a cell wall.

Which of the following is not one of the four postulates of disease developed by Koch? a. The same organism must be present in every case of the disease b. The isolated organism should cause the disease in question when it is introduced to a susceptible host. c. The organism must be re-isolated from the inoculated, diseased animal. d. The organism should be present in mixed culture.

The organism should be present in mixed culture.

Animals are not typically microscopic, yet we cover them in microbiology because ____. a. many pathogenic animals are unicellular b. certain parasitic worms, or helminths, are usually spread in a microscopic form c. their cell walls may contain virulence factors that cause infections in humans d. they contain chloroplasts that may cause allergic reactions in immunocompromised patients

certain parasitic worms, or helminths, are usually spread in a microscopic form

____ is to fungal cell walls as ____ is to bacterial cell walls. a. Chitin; peptidoglycan b. Chitin; pseudomurein c. Cellulose; peptidoglycan d. Cellulose; chitin

chitin; peptidoglycan

You receive results back from the lab that your patient is infected with Vibrio cholera. This organism is a ____ - shaped organism. a. rod b. spherical c. comma d. spiral

comma

Which of the following type of fungal spores arise from mitosis and do not result in genetic variation? a. ascospores b. conidiospores c. zygospores d. basidiospores

conidiospores

Which type of reaction is shown? A + B --> AB + H2O a. decomposition reaction by hydrolysis b. single exchange reaction c. dehydration synthesis reaction d. decomposition reaction

dehydration synthesis reaction

The building blocks of nucleic acids are ____. a. simple sugars b. waxes c. deoxyribonucleotides or ribonucleotides d. amino acids

deoxyribonucleotides or ribonucleotides

Which of the following is not an accomplishment that is attributed to Louis Pasteur? a. developing the first vaccine to protect against anthrax b. demonstrating that yeast performed fermentation c. disproving spontaneous generation d. developing the postulates of disease

developing the postulates of disease

Which of the following is the most general classification of an organism? a. strain b. domain c. species d. genus

domain

Which of the following eukaryotic organelles plays an essential role in protein and lipid production in the cell? a. endoplasmic reticulum b. golgi apparatus c. nucleus d. mitochondria

endoplasmic reticulum

Which of the following cellular structures is matched with their correct function? a. pili - build proteins by linking together amino acids b. glycocalyx - contains stored materials to be used for later tasks c. fimbriae - allow a cell to stick to surfaces or each other d. ribosomes - use to adhere to surfaces, move, and aid in gene transfer through conjugation

fimbriae - allow a cell to stick to surfaces or each other

Which of the following is not a domain? a. bacteria b. fungi c. eukarya d. archaea

fungi

You are observing an unknown, unicellular organism with a high-resolution microscope. You are noting the presence of various membrane-bound organelles. Which of the following types of cells are you likely working with? a. a type of helminth b. an archaeal organism c. fungus d. bacterial organism

fungus

The organism Candida albicans is classified as a ____ and grouped within the domain ____. a. fungus; Eukarya b. fungus; Monera c. bacterium; Monera d. bacterium; Bacteria

fungus; Eukarya

The sticky outer layer that can be found in both prokaryotic and eukaryotic cells is known as the ____. a. glycocalyx b. cilia c. cell wall d. flagella

glococalyx

Which of the following would not be a building block of a nucleotide? a. nitrogenous base b. five-carbon sugar c. phosphate group d. glucose molecule

glucose molecule

A colony (is a ) ___. a. mixed culture b. helps isolate a specific species of microbe for study c. pure culture d. grouping of cells that developed from a single parent cell

grouping of cells that developed form a single parent cell

Which of the following regions in the human body supports the greatest variety of microbial species? a. urogenital tract b. gut c. skin d. mouth, pharynx, upper respiratory system

gut

While many areas on and in the human body contain a variety of microbes, there are "microbe-free zones." Which of the following would not typically be a microbe-free zone? a. uterus b. human gut c. blood d. brain

human gut

Which of the following would be the weakest bond? a. polar covalent bond b. hydrogen bond c. covalent bond d. ionic bond

hydrogen bond

You are working with a substance that readily dissolves in water. It is said to be ____. a. hydrophobic b. micelles c. hydrophilic d. amphipathic

hydrophilic

Chloride (Cl-) is most likely to form a(n) ____ bond with ____. a. ionic; Na+ b. ionic; OH- c. covalent; Na+ d. hydrogen; H+

ionic; Na+

14C is an ____ of ____. a. isotope; calcium b. ion; carbon c. isotope; carbon d. ion; calcium

isotope; carbon

Which of the following vesicles contain a wide variety of hydrolytic enzymes that break down substances engulfed by the cell during phagocytosis? a. peroxisomes b. lysosomes c. vacuoles d. secretory vesicles

lysosomes

which of the following fibers are found as part of the eukaryotic cytoskeleton? a. microtubules, intermediate filaments, and microfilaments b. microtubules and intermediate filaments only c. intermediate filaments and microfilaments only d. microfilaments and microtubules only

microfilaments, intermediate filaments, and microfilaments

Eukaryotic cells are not found in which of the following kingdoms? a. plantae b. fungi c. monera d. animalia

miners

Which of the following statements about electron microscopy is false? a. It only produces black and white images. b. It has a maximum magnification of 1000x. c. All observed specimen are dead. d. It requires lengthy and complex sample preparation.

It has a maximum magnification of 1000x.

Which of the following is an incorrect statement about aseptic technique? a. It is a sterile technique. b. Aseptic processes are central to health care. c. It was first developed by Ignaz Semmelweis. d. It is used to prevent contamination.

It is a sterile technique.

Which of the following scientists investigated processes for aseptic surgery? a. Alexander Fleming b. Joseph Lister c. Edward Jenner d. Robert Koch

Joseph Lister

The endosymbiotic theory states that nonphotosynthetic prokaryotes merged with an ancestral cell and, over evolutionary time, became ____. Some of these new cells engaged in a second merging event with a new photosynthetic prokaryote, possibly a cyanobacterium. The photosynthetic prokaryote eventually-over evolutionary time- became ____. a. mitochondria; chloroplasts b. chloroplasts; mitochondria c. nucleus; chloroplasts d. ribosomes; mitochondria

mitochondria; chloroplasts

A(n) ____ is formed when two or more atoms bond together; a(n) ____ is used to describe molecules that are composed of more than one type of element. a. ion; compound b. compound; molecule c. molecule; ion d. molecule; compound

molecule; compound

The DNA of a prokaryotic cell is found within the ____. a. periplasmic space b. nucleoid region c. nucleus d. ribosome

nucleoid region

Which of the following cell structures are only found in eukaryotic cells? a. ribosomes b. flagella c. plasma membrane d. nucleus

nucleus

The Golgi apparatus: a. is made up of fine fibers made of the protein actin b. is made up of lipid bilayer sacs packed with substances ranging from simple organic and inorganic molecules to complex enzymes c. is enclosed by a double-membrane structure d. resembles a series of disc-like, flattened sacs called cisternae that stack upon one another

resembles a series of disc-like, flattened sacs called cisternae that stack upon one another

Which biological molecule is shown in the picture? a. glycogen b. unsaturated fatty acid c. saturated fatty acid d. amino acid

saturated fatty acid

You are interested in the alpha helices present in a novel protein. In order to study them, you must consider the ____ structure of a protein more closely. a. quaternary b. primary c. secondary d. tertiary

secondary

We explore questions about the origins of disease though the scientific method. Which of the following would be the most likely order to apply the scientific method? a. formulate hypothesis - state question - design experiment - collect data - draw conclusions b. design experiment - formulate hypothesis - state question - collect data - draw conclusions c. state question - formulate hypothesis - design experiment - collect data - draw conclusions d. design experiment - collect data - formulate hypothesis - state question - draw conclusions

state question - formulate hypothesis - design experiment - collect data - draw conclusions

Escherichia coli O157:H7 may cause sever illness. "O157:H7" is the ____ designation of the organism. a. domain b. species c. strain d. genus

strain

You are observing an unknown organism under the microscope. The organism is spherical and arranged in long chains. You are observing ____. a. staphylococci b. coccobacilli c. streptococci d. spirochetes

streptococci

Which of the following is not a feature of eukaryotic flagella? a. they contain microtubules b. they are membrane-enclosed c. they are built from flagellin proteins d. the flagella move in a wave-like motion.

they are built from flagellin proteins

Which of the following microscopy terms is correctly matched with its definition? a. refractive index - ability to distinguish two points as separate points b. resolution - degree to which a substance bends light c. oil immersion - oil used at 100x total magnification to prevent light from scattering d. total magnification - the magnification resulting from multiplying the magnification of the ocular and object lenses

total magnification - the magnification resulting from multiplying the magnification of the ocular and objective lenses

Which of the following microbes is considered "nonliving?" a. fungi b. bacteria c. archaea d. viruses

viruses

The organism Mycobacterium tuberculosis makes mycolic acid, which is deposited in the bacterial cell wall and acts as a protective barrier for the cell and increases bacterial pathogenicity. Mycolic acid would be an example of a(n) a. simple sugar b. amino acid c. steroid d. wax

wax

Which of the following statements is incorrect? a. Ribosomes are membrane-bound organelles that aid in protein synthesis. b. Ribosomes are made up of two subunits; in prokaryotes the larger subunit is called 50S and the smaller 30S. c. Prokaryotic ribosomes are overall smaller in mass and diameter than eukaryotic ribosomes. d. Prokaryotic ribosomes are a great target for antibiotics due to their structural difference to eukaryotic ribosomes.

Ribosomes are membrane-bound organelles that aid in protein synthesis.

Which of the following is an incorrect statement about teichoic acids found in Gram-positive cell walls? a. Teichoic acids help maintain shape of a bacterial cell and aid in regulation of cell division. b. Teichoic acids promote adhesion to host tissues and protect Gram-positive bacteria from various antimicrobial compounds. c. Teichoic acids stabilize the cell wall. d. Teichoic acids are not found in the cell wall of a Gram-positive organism; they are only found in Gram-negatives.

Teichoic acids are not found in the cell wall of a Gram-positive organism; they are only found in Gram-negatives.

Most prokaryotic cells reproduce ____ through a process called ____. a. asexually; meiosis b. sexually; binary fission c. asexually; binary fission d. asexually; mitosis

asexually; binary fission

Which of the following types of cell division is found in prokaryotic cells? a. meiosis b. mitosis c. all types-binary fission, mitosis, and meiosis-are found in prokaryotic cells d. binary fission

binary fission

The success of the Gram-stain is based on the difference in the composition of the ____ of bacterial cells. a. capsules b. flagella c. cell walls d. plasma membranes

cell walls

The sodium ion is noted as Na+ because it has an overall charge of ____. a. +2 b. +1 c. It cannot be determined as written. d. -1

+1

Most prokaryotes are between ____ in size. a. 0.5 and 2.5 nm b. 650 and 750 μm c. 1 and 10 nm d. 0.5 and 2.0 μm

0.5 and 2.0 μm

Based on your knowledge of binary fission in prokaryotes, how many cells would be present after four cycles of cell division if you started with two cells? a. 32 b. 16 c. 8 d. 4

32

Eukaryotic ribosomes are made up of a small ____ subunit and large ____ subunit. a. 40S; 60S b. 40S; 80S c. 30S; 50S d. 70S; 80S

40S; 60S

You are administering a 5% dextrose in water solution to your patient to replace lost fluids and provide carbohydrates to the body. How much dextrose was added to 1 liter of water? a. 500g/L b. 5g/L c. 50g/L d. It cannot be determined as written

50g/L

You suspect that your patient is suffering from tuberculosis and obtain a sputum sample. Which of the following staining procedures would be the most appropriate to diagnose your patient? a. capsule stain b. gram stain c. flagellar stain d. acid-fast stain

An acid-fast stain would be the best staining method for a sputum sample obtained from a patient that you are suspecting is suffering from tuberculosis. The cell wall of Mycobacterium tuberculosis, the causative agent of tuberculosis, contains mycolic acid, a waxy layer that is not easily penetrated. A flagellar stain is helpful to highlight the number and position of flagella in microbes. Mycobacterium tuberculosis use a non-motile organism and a flagellar stain would not be helpful to identify the organism. A capsule stain is used to highlight sticky carbohydrate-based structures that some bacteria produce as a form of protection and also to help them adhere to surfaces. Mycobacterium tuberculosis does not form capsules, thus this staining procedure would not be helpful to identify this organism.

Nematodes, tapeworms, and flukes are members of the kingdom ____. a. Animalia b. Fungi c. Protista d. Plantae

Animalia

____ was the first scientist to observe bacteria under the microscope. a. Robert Koch b. Robert Hooke c. Joseph Lister d. Antonie van Leeuwenhoek

Antonie van Leeuwenhoek

Archaeal plasma membranes differ from bacterial plasma membranes. Which of the following is not a major structural difference? a. In bacterial membranes, fatty acids are joined to glycerol by an ester bond, while archaea use an ether bond. b. Bacteria and archaea use different building blocks for their membrane phospholipids. c. Some archaeal plasma membranes may be lipid monolayers as opposed to lipid bilayers. d. Bacterial plasma membranes contain peptidoglycan while archaeal plasma membranes contain pseudomurein.

Bacterial plasma membranes contain peptidoglycan while archaeal plasma membranes contain pseudomurein.

Which of the following statements is incorrect about endospores? a. The most medical relevant spore-formers are found in the Bacillus and Clostridium genera. b. Most spore-forming prokaryotes are Gram-positive. c. Endospores are highly resistant to environmental stress. d. Endospores are reproductive structures.

Endospores are reproductive structures.

Your patient has severe diarrhea and is passing mucus and blood. Stool samples that were obtained and checked under a microscope reveal cysts. His patient history also indicates that he recently traveled to southeast Asia. What is he likely infected with? a. Acanthamoeba b. Entamoeba histolytica c. Euglena d. Naegleria fowleri

Entamoeba histolytica

Which of the following is characterized as a Mastigophora, or "flagellated protozoan"? a. Plasmodium species b. Entamoeba histolytica c. Balantidium coli d. Giardia intestinalis

Giardia intestinalis

Which of the following statements about hydrogen bonds is incorrect? a. Hydrogen bonds can exist between two or more individual molecules. b. Hydrogen bonds are a covalent electrostatic attraction between two or more molecules. c. A hydrogen bond is an electrostatic interaction between dipoles. d. Water contains an abundance of hydrogen bonds.

Hydrogen bonds are covalent electrostatic attraction between two or more molecules.

Which of the following provides supporting evidence that mitochondria and chloroplasts may have once been free-living prokaryotes? a. Mitochondria and chloroplasts are relatively large organelles. b. Mitochondria and chloroplasts contain 70S ribosomes. c. Mitochondria and chloroplasts have similar function in that they are responsible for generating most of the cell's ATP. d. Mitochondria and chloroplasts are non-membrane bound organelles.

Mitochondria and chloroplasts contain 70S ribosomes.

Which of the following is an incorrect statement about pH? a. Most microbes grow best at a pH between 5 and 6. b. Some environments have a recorded pH lower than 1. c. Acids contribute hydrogen ions (H+) to an aqueous solution. d. Bases contribute hydroxide ions (OH-) to an aqueous solution.

Most microbes grow best at a pH between 5 and 6.

Which of the following molecules would not change the pH of an unbuffered solution? a. NaOH b. H2SO4 c. NaCl d. HCl

NaCl

Which of the following is a correct statement about polar substances? a. The plasma membrane is said to be a polar structure. b. Polar, or hydrophilic, substances readily dissolve in water. c. Polar molecules form micelles when exposed to an aqueous environment. d. Fats and vitamins like A and D are considered polar molecules.

Polar, or hydrophilic, substances readily dissolve in water.

The picture shows the amino acid tryptophan. The highlighted group in green is also known as the ____. a. amine b. R group c. adenine d. carboxyl

R group

Which of the following functional groups is matched with its correct name? a. R-COOH; ether group b. R-OH; hydroxyl group c. R-NH2; methyl group d. R-CH3; ester group

R-OH; hydroxyl group

Which of the following vesicles contain a wide variety of hydrolytic enzymes that break down substances engulfed by the cell during phagocytosis? a. Candida species b. Pneumocystis species c. Claviceps purpurea species d. Trichophyton species

Trichophyton species

If you left out the safranin from your Gram staining procedure and observed your mixed culture after the application or alcohol-acetone, what would be the appearance of your Gram-positive and Gram-negative organisms, given that you followed all steps in order and applied all other reagents correctly? a. your Gram-positives would appear pink, Gram-negatives would be purple. b. Your Gram-positives would appear purple, and your Gram-negatives would be pink. c. Your Gram-positives would appear purple, and your Gram-negatives would be colorless. d. Your Gram-positives would appear pink, Gram-negatives would be colorless.

Your Gram-positives would appear purple, and your Gram-negatives would be colorless. This would be the only possible outcome. The cell wall of Gram-positive organisms contains about 90% peptidoglycan. During the decolorization process, the alcohol-acetone dehydrates the cell wall and retains crystal violet, causing it to appear purple. The cell wall of Gram-negatives contains only 10% peptidoglycan. Alcohol-acetone dissolves most of the cell wall, thus allowing for the crystal violet to be "washed" out. Without the application of a counterstain, those cells would consequently appear colorless.

The cytoplasmic membrane could best be described as ____. a. a highly selective, permeable barrier b. an impermeable barrier c. a barrier that may or may not be present, depending on the microorganism d. a rigid structure that protects the cell

a highly selective, permeable barrier

Which of the following definitions is correctly matched? a. exergonic reaction - when the products of a reaction have a higher final energy than the reactants b. endergonic - a type of reaction that releases more energy than is spent c. equilibrium - static process where forward and reverse reactions have occurred at the same rate d. activation energy - the minimum amount of energy needed to get a reaction started

activation energy - the minimum amount of energy needed to get a reaction started

Which of the following types of transport would only be found in living cells? a. facilitated diffusion b. active transport c. diffusion d. osmosis

active transport

The flagellar arrangement seen in the picture can be describes as ____. a. lophotrichous b. monotrichous c. amphitrichous d. peritrichous

amphitrichous

You identify a novel living organism that needs to be classified into one of the three domains of life. The organism has a cell wall containing pseudopeptidoglycan (pseudomurein), a plasma membrane, and a nucleotide region. Based on this information, which of the three domains would be the correct classification? a. archaea only b. prokaryotes c. bacteria and archaea d. bacteria only

archaea only

Plants ____. a. may cause infectious disease b. are saprobes c. are multicellular organisms that carry out photosynthesis d. are characterized as a group that contains both unicellular or multicellular organisms

are multicellular organisms that carry out photosynthesis

A symbiotic relationship exists between two or more closely connected organisms. The relationship between one organism invading another and causing harm to that organism would be considered ____. a. planktonic b. parasitism c. commensalism d. mutualism

parasitism A symbiotic relationship exists between two or more closely connected organisms. The relationship between a disease-causing organism and the human suffering from the disease would be considered parasitism. Pathogens are described as having a parasitic relationship with their host. Commensalism describes the relationship between an organism and its host in which only the organism would benefit but no perceived benefit or cost to the host would be perceived. Mutualism describes the relationship between an organism and its host in which both the organism and host benefit from each other. Planktonic is the term used to describe "free-floating" bacteria.

Which of the following molecules is not found in the plasma membrane? a. cholesterol b. peptidoglycan c. phospholipids d. proteins

peptidoglycan

Whole cells or viruses are engulfed and important into a eukaryotic cell via ____. a. phagocytosis b. pinocytosis c. exocytosis d. diffusion

phagocytosis

Which of the following cell structures is found in all cells? a. nucleus b. cell wall c. plasma membrane d. mitochondria

plasma membrane

Which of the following structures is found in all cells? a. cilia b. plasma membrane c. nucleus d. cell wall

plasma membrane

Which of the following structures is not found in a Gram-negative cell wall? a. periplasmic space b. plasma membrane c. peptidoglycan d. LPS layer

plasma membrane

Each element is identifies by their atomic number, or number of ____. a. electrons b. protons c. elements d. neutrons

protons

____ are just temporary passengers that do not persist as stable residents of our bodies. a. normal microbiota b. bioremediation c. resident microbiota d. transient microbiota

transient microbiota Transient microbes are just temporary passengers that do not persist as stable residents of our bodies and are not very well adapted to the human body. Many times they are picked up through a handshake or contact with environmental surfaces. Unlike normal microbiota, transient microbiota can be easily removed through hygiene, especially via proper hand-washing technique. Resident or "normal" microbiota include bacteria, archaea, and eukaryotic microbes. They train our immune system, produce vitamins for us, and help us digest foods. Studies suggest that they may even impact our moods and brain function. Bioremediation harnesses the power of microbes to help clean up toxic waste in the environment.

Which of the following types of microscopy would be best to study how a novel virus interacts with its host cell? a. dark field microscopy b. transmission electron microscopy c. fluorescent microscopy d. brightfield microscopy

transmission electron microscopy

Prokaryotic cells move in response to a wide variety of stimuli. Which of the following types of movement is incorrectly matched? a. aerotaxis - movement in response to oxygen levels b. phototaxis - movement in response to light c. tumble - movement in a concerted direction toward or away from a stimulus d. chemotaxis - movement in response to a chemical stimulus

tumble - movement in a concerted direction toward or away from a stimulus