Exam 1

How is phagocytosis in the immune system different from protozoan phagocytosis?

a a. Protozoan phagocytosis is used for feeding; phagocytosis by immune cells is used to fight infection. b. There is no difference between the two. c. Protozoan phagocytosis is used to fight infection; phagocytosis by immune cells is used to feed the cells.

Which grouping of parasitic helminths includes hookworms?

a a. Roundworms b. Flatworms c. Cestodes d. Flukes

Which statement does not describe helminthic parasites?

b a. All belong to one of two groups: roundworms or flatworms. b. All are hermaphroditic. c. All tend to have complex life cycles that can involve different host species. d. An important mode of transmission is ingestion of the eggs or organism from feces-contaminated food and water. e. All reproduce sexually.

Why aren't Archaea discussed as much as bacteria?

b a. Archaea are only found in a few limited environments. b. Archaea haven't been linked to human diseases. c. Archaea are not part of the human microbiome. d. Archaea infections are easy to treat. e. Archaea only live in extreme environments.

Which of the following is correctly written, based upon the rules of the binomial nomenclature system?

b a. Escherichia coli b. Escherichia coli (italicized) c. Escherichia Coli (italicized) d. Escherichia coli (italicized and underlined)

Choose the false statement about cellular transport mechanisms.

b a. Facilitated diffusion does not require energy and uses membrane proteins to move substances down their concentration gradient. b. Diffusion is the passive movement of substances from areas of low concentration to areas of high concentration. c. Osmosis is the passive movement of water from a low-solute concentration to a high-solute concentration. d. Active transport requires energy and uses carrier proteins to move substances against their concentration gradient.

Regarding Gram-positive versus Gram-negative bacteria, which of the following is false?

b a. Gram-positive bacteria are more likely to withstand mechanical stresses like crushing. b. Gram-negative bacteria are more likely to be susceptible to penicillin. c. Gram-positive bacteria are more likely to tolerate dry environments. d. Gram-positive bacteria are more likely to be susceptible to anionic detergents. e. Gram-negative bacteria are more likely to be non-acid-fast.

_____________ bacteria lack an outer membrane, have a thick layer of peptidoglycan, contain teichoic acid, and lack mycolic acid.

b a. Gram-variable b. Gram-positive c. Gram-negative d. Acid-fast

Choose the true statement regarding Lister's contribution to health care.

b a. He established innovations in nursing practices. b. He developed aseptic surgery practices. c. He was the first to recommend hand-washing to decrease infection rates in patients. d. He disproved spontaneous generation.

What is the function of a carboxysome?

b a. It stores carbon in a cell. b. It houses carbon-fixation enzymes. c. It stores energy for cellular work. d. It protects against oxygen radicals. e. It serves as a magnetic compass.

What does the plasma membrane of a phagocyte attach to on a microorganism?

b a. Pseudopods b. Glycoproteins c. Lysosomes d. Phagosomes

Explain the differences between a hypothesis, law, and theory.

A hypothesis is a limited explanation of a phenomenon; a scientific theory is an in-depth explanation of the observed phenomenon. A law is a statement about an observed phenomenon or a unifying concept

A bacteria's DNA can be found in the nucleus of the cell.

False

A capsule is one type of glycocalyx that is fairly unorganized and loosely associated with the cell wall.

False

Binary fission is more complicated than mitosis.

False

Florence Nightingale investigated processes for aseptic surgery and her work in the 1860s proved that sterilizing instruments, and sanitizing wounds with carbolic acid encouraged healing and prevented pus formation.

False

Prokaryotic cells that move in response to oxygen levels are said to display chemotaxis.

False

Proper hand-washing technique can remove normal microbiota.

False

Protozoan infections are common in (though definitely not limited to) developing countries where limited medical and laboratory facilities may hinder diagnosis. Each of the four groups of protozoans may be identified by certain characteristics visible under the microscope. Name the groups and explain those characteristics which lead to identification.

Protozoans are grouped based on their means of mobility in their mature form; amoeboid, flagellated, ciliated, spore forming. Amoeboid protozoans use "false feet"—extensions of their cytoplasm called pseudopods for movement, flagellated protozoa have one or more flagella for motility, ciliated protozoa use hair-like appendages called cilia for motility, and spore forming protozoa have no flagella, cilia, or pseudopodia, and instead move by gliding

Bacteria that have flagella at both poles of the cell are described as amphitrichous.

True

Bacteria that have periplasmic flagella always have a spirochete shape.

True

Gram-positive bacteria stain purple when the Gram stain is complete.

True

Only a small minority of microbes are human pathogens.

True

Spirochetes move in a corkscrew-rotary motion due to a specialized periplasmic flagellum.

True

How does the cell wall of bacteria and archaea differ?

a a. Bacteria use peptidoglycan. b. Bacteria have a lot of diversity in the makeup of their cell walls. c. Archaea use peptidoglycan. d. Bacteria use pseudopeptidoglycan. e. Archaea have little diversity in the makeup of their cell walls.

Which of the following does not represent a shape or arrangement that a prokaryote can assume?

a a. Clusters of bacilli form a Staph arrangement. b. Stella are star shaped cells. c. Clusters of bacilli form a Pallisade arrangement. d. Vibrio are comma shaped cells.

Which of the following is true about endospores?

a a. Endospores are highly resistant to environmental stress. b. Endospores are considered reproductive structures. c. Endospores are metabolically active structures. d. Endospores are only viable for a short time. e. Endospores are susceptible to various chemicals.

Why are chemical agents like lysozyme more likely to damage Gram-positive bacteria than Gram-negative bacteria?

a a. Gram-negative bacteria have an outer membrane as part of their cell wall. b. Gram-negative bacteria have porins. c. Gram-negative bacteria have a thin peptidoglycan layer in their cell wall. d. Gram-negative bacteria have a thicker peptidoglycan layer in their cell wall. e. Gram-negative bacteria lack a cell wall.

What happens when you place a bacterial cell with an intact cell wall into a hypertonic solution?

a a. It undergoes plasmolysis. b. It undergoes lysis. c. There will not be an effect on the cell. d. The cell will burst. e. The cell will swell.

Choose the true statement(s) about normal microbiota. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

a a. Our normal microbiota help to train our immune system. b. Human normal microbiota are found in all body sites. c. Our normal microbiota do not include potential pathogens. d. Our normal microbiota only include bacteria.

________ bacteria can create sticky communities called ________, which are made up of single or diverse microbial species.

a a. Planktonic; biofilms b. Matrix; cavities c. Pathogenic; quorums d. Plaque; hangouts e. Infectious; flora

Choose the statement which best defines a pleomorphic organism.

a a. Pleomorphic organisms can take on different forms, which enhances their survival and transmission to a human host. b. Pleomorphic organisms can alter their size but not their shape. c. Pleomorphic organisms do not impact an organism's ability to form a biofilm. d. Pleomorphic organisms lack the ability to take on different forms such as shape or arrangement.

Which of the following is false about the bacterial cytoskeleton?

a a. The bacterial cytoskeleton contains actin and tubulin proteins. b. The bacterial cytoskeleton acts as scaffolding to organize cell division. c. The bacterial cytoskeleton is composed of long protein filaments. d. The bacterial cytoskeleton provides an overall general organization to the cytoplasm for a variety of biochemical processes. e. The bacterial cytoskeleton directs the construction of the rigid cell wall.

Considering the process of osmosis, what will occur if a bacterial cell is put into a hypotonic solution?

a a. The cell will take on water and may lyse if its cell wall is damaged. b. There will be no net movement of water into or out of the cell. c. The cell will absorb salt from its environment. d. The cell will lose water and undergo plasmolysis.

The process by which a phagocyte moves toward a chemical signal at the site of an infection is called

a a. chemotaxis. b. adherence. c. digestion. d. exocytosis. e. elimination.

Bacteria with flagella distributed all over the cell surface are described as having:

a a. peritrichous flagella b. periplasmic flagella c. monotrichous flagella d. lophotrichous flagella e. amphitrichous flagella

Choose the true statement(s) about spore-forming bacteria. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

a and c a. Spore-forming bacteria, such as Clostridium, contain heat- and chemical-resistant layers around the spore coat, making them difficult to destroy. b. Spores contain a low amount of dipicolinic acid, which contributes to the heat resistance of spores. c. Disinfectants such as bleach are sporicidal and are effective in destroying spores. d. Only gram-positive organisms are spore forming.

Choose the true statement(s) about the taxonomic hierarchy and its vocabulary terms. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

a and c a. The five-kingdom classification scheme includes: Animalia, Plantae, Fungi, Protista, and Monera. b. Bacterial species are defined as a group of organisms that can reproduce or breed together. c. An example of a domain is Archaea. d. The taxonomic hierarchy sequence is: domain, kingdom, class, phylum, order, family, genus, species.

Select the true statement(s) regarding the scientific method. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

a and d a. A hypothesis is a prediction and is proposed as a potential answer to a question. b. A conclusion is any data gathered using our senses or testing, whereas an observation interprets conclusions. c. In terms of science, theories that stand the test of time are eventually elevated to laws. d. A theory is a hypothesis that has been proven through many studies with consistent, supporting conclusions.

Choose the true statement(s) about the prokaryotic cytoskeleton. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

a and d a. The prokaryotic cytoskeleton directs construction of a rigid cell wall. b. The prokaryotic cytoskeleton contains standard actin and tubulin proteins. c. The prokaryotic cytoskeleton acts as a scaffolding to organize mitosis. d. The prokaryotic cytoskeleton provides general organization of the cytoplasm.

Choose the true statement(s) about acid-fast bacteria. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

a, b, and c a. Acid-fast staining is important in the diagnosis of leprosy and tuberculosis. b. Acid-fast bacteria have a waxy lipid called mycolic acid in their cell walls. c. Genera Nocardia and Mycobacterium are acid-fast and stain pink during the acid-fast staining procedure. d. Genera Nocardia and Mycobacterium are acid-fast and stain blue during the acid-fast staining procedure.

Choose the true statement(s) about binary fission in prokaryotic cells. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

a, c, and d a. Binary fission frequency differs between species and is affected by environmental conditions. b. Binary fission is a type of sexual reproduction which introduces genetic variation from parent to offspring. c. Binary fission is a type of asexual reproduction that is simpler than mitosis. d. Binary fission results in offspring, which are genetically identical to the parent cell.

Choose the true statement(s) about prokaryotic external appendages. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

a, c, and d a. Pili allow for adhesion, movement, and aid in gene transfer through conjugation. b. Fimbriae aid in gene transfer through conjugation. c. Flagella allow for motility. d. The glycocalyx promotes adhesion and interferes with phagocytosis.

Why are most prokaryotic cells small?

b a. Storage bodies within a cell enable cells to be small so they need less nutrients. b. Nutrient diffusion is most efficient for smaller cells. c. A low surface area-to-volume ratio helps smaller cells divide easier. d. Intracellular inclusions demand that cell size be small. e. A high surface area-to-volume ratio helps smaller cells divide easier.

Which of the following is true regarding the bacterial plasma membrane only, and not the archaeal plasma membrane?

b a. Tetraether lipids are adaptations, which allow bacteria to thrive in harsh, extreme environments. b. The bacterial plasma membrane only occurs as a bilayer. c. The plasma membrane is made up primarily of phospholipids. d. The bacterial plasma membrane occurs as a monolayer or in a bilayer format.

Choose the false statement regarding prokaryotic plasma membranes.

b a. The plasma membrane's phospholipid bilayer contains hydrophilic phosphates and hydrophobic fatty acids. b. Ions and large polar substances can diffuse through the plasma membrane without assistance. c. The plasma membrane is a phospholipid bilayer that serves as barrier for a cell. d. Gases, water, and small non-charged substances can diffuse through the selectively permeable plasma membrane.

Which group is not a kingdom-level classification of eukaryotic organisms?

b a. animals b. protozoa c. fungi d. protista e. plants

Most prokaryotic cells reproduce

b a. by meiosis. b. by binary fission. c. sexually. d. by mitosis. e. extremely quickly.

Which of the following structures allow bacteria to transfer genetic information through conjugation?

b a. glycocalyx b. pili c. fimbriae d. capsule e. slime layer

Which of the following is not a microorganism?

b a. helminth b. mosquito c. archaea d. bacteria e. fungi

The genetic material of bacteria can be found in the

b a. nucleolus. b. nucleoid. c. cytoskeleton. d. nucleus. e. nucleosome.

Which of the following arrangements is sometimes referred to as having a beads-on-a-string appearance?

b a. palisade b. streptococci c. diplococci d. streptobacilli e. staphylococci

Prokaryotic cells house a single circular chromosome in their __________.

b a. ribosomes b. nucleoid region c. periplasmic space d. nucleus

When do opportunistic pathogens tend to cause disease?

b a. when the host is old b. when the host is weakened c. when the host didn't wash with soap d. after the host is already infected with a different pathogen e. when the host is young

Select the true statement(s) about microbes. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

b and c a. The domain Archaea does not include microbes. b. Viruses and prions are considered microbes. c. Some microbes are visible to the naked eye. d. Most microbes are pathogens.

Choose the true statement(s) about protists. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

b and c a. Protists only reproduce by asexual means. b. Protists can be photosynthetic or heterotrophic. c. The term protozoan describes animal-like protists but is not a true taxonomic ranking. d. Protozoans are multicellular protists.

Choose the true statement(s) about prokaryotic cells. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

b, c, and d a. Prokaryotes do not change shape or arrangement to enhance their survival. b. All prokaryotes are unicellular organisms. c. Most of a prokaryote's nutrients are obtained through diffusion. d. All prokaryotes lack a membrane-bound nucleus and organelles.

Choose the true statement(s). To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

b, c, and d a. Protists are strictly unicellular. b. Kingdom Fungi includes unicellular and multicellular organisms. c. The four kingdoms of eukaryotes each include members that may conduct sexual and/or asexual reproduction. d. The four kingdoms of eukaryotes include Animalia, Plantae, Fungi, and Protista.

What is a phagolysosome?

c a. A vesicle containing only digestive enzymes and other antimicrobial compounds. b. A protein that covers the surface of an invading microbe, making it easier for the phagocyte to ingest. c. The structure that results from the fusion of a phagosome and a lysosome. d. A vesicle containing only an engulfed invading microorganism.

Which of the following are bacteria that initially had a cell wall and lost it either through the course of their life cycle or due to mutation?

c a. Acid-fast bacteria b. Members of the genus Mycoplasma c. L-form bacteria d. Members of the genus Mycobacterium

Which of the following phagocytic processes occurs last in the sequence?

c a. Adherence b. Formation of the phagolysosome c. Exocytosis d. Chemotaxis of the phagocyte to the site of infection

Choose the true statement about the Domain Bacteria.

c a. Bacteria inhabit extreme environments and are not linked to human diseases. b. The Domains Bacteria and Archaea are genetically identical. c. The Domain Bacteria is made up of prokaryotes and likely originated 3.8 billion years ago. d. The Domain Eukarya is more closely related to the Domain Bacteria than to the Domain Archaea.

Which of the following is the correct way to type a scientific name?

c a. Escherichia Coli b. Escherichia coli (italicized and underlined) c. Escherichia coli (italicized) d. escherichia coli (italicized and underlined) e. escherichia coli (underlined)

Choose the features of the prokaryotic ribosome that support the endosymbiotic theory.

c a. Prokaryotic ribosomes build proteins by linking amino acids together. b. Prokaryotic ribosomes have a lower overall mass and diameter compared to eukaryotic ribosomes. c. Prokaryotes have a ribosome with a 70S sedimentation rate. d. Prokaryotes have a ribosome with a 80S sedimentation rate.

Cells may directly increase their plasma membrane fluidity by:

c a. Reducing the number of double bonds in the hydrocarbon chains of their phospholipids. b. Moving to colder temperatures. c. Adding cholesterol to their phospholipid bilayer. d. Decreasing the amount of unsaturated fatty acids in their phospholipids. e. Building their lipid bilayer out of longer phospholipids.

Select the incorrect pairing.

c a. Slime layer: a fairly disorganized sticky carbohydrate-enriched layer b. Capsule: A carbohydrate layer that aids bacterial adhesion to host tissues c. Glycocalyx: a carbohydrate layer found within the cell wall d. Fimbriae: structures that are important to helping cells form biofilms e. Pili: protein structures that may aid in cell movement

Which of the following is NOT one of Koch's postulates of disease?

c a. The same organism must be present in every case of a disease. b. The organism must be re-isolated from the inoculated diseased animal. c. The organism may cause a different disease in some infected individuals. d. The organism must be isolated from the infected host and grown in pure culture.

Short, bristle-like structures that extrude from the surface of a prokaryotic cell are called

c a. mating bridges b. flagella. c. fimbriae. d. pili. e. cilia.

Normal microbiota are responsible for all of the following except

c a. producing vitamins for us. b. training our immune system. c. controlling epigenetic expression. d. helping us digest foods. e. impacting our moods and brain functions.

Membrane proteins perform all of the following functions except

c a. receptors. b. enzymes. c. blocks. d. transporters. e. anchors.

Most helminthic parasites spend at least some part of their life cycle in the

c a. skin. b. respiratory tract. c. gastrointestinal tract. d. genitourinary tract. e. cardiovascular system.

Select the true statement(s) about a scientific name for an organism. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

c and d a. An organism's taxonomic family is reflected in its first name. b. The organism's phylum designation is described by its second name. c. An organism's name may refer to its discoverer, the organism's shape and/or arrangement, or other distinct traits. d. A scientific name for an organism consists of two names.

How many principles are there in Koch's postulates of disease?

d a. 1 b. 2 c. 3 d. 4 e. 5

Why is it so difficult to kill acid-fast bacteria?

d a. Acid-fast bacteria have a thick peptidoglycan layer that protects them. b. Acid-fast bacteria make endospores and can go dormant to avoid drug therapies. c. Acid-fast bacteria make acids that inactivate antibiotics. d. Acid-fast bacteria have mycolic acid in their cell walls, which limits drug entry. e. Acid-fast bacteria divide rapidly, making it hard to limit their population

Which of the following statements is false?

d a. Archaea and Bacteria are prokaryotic domains. b. Eukarya is a eukaryotic domain. c. Eukaryotic cells evolved from prokaryotic cells. d. Eukaryotes have a much simpler genetic makeup than prokaryotic cells. e. Prokaryotes are unicellular and lack a membrane-bound nucleus.

Which of the following is mismatched?

d a. Basidiospores: sexual spores found in mushroom b. Zygospores: sexual reproduction c. Sporangiospores: asexual spores d. Ascospores; asexual reproduction

Select the false statement about fungal infections.

d a. Coccidioidomycosis is a respiratory disease also known as Valley Fever. b. Vaginal yeast infections are caused by Candida species. c. Tinea pedis is caused by Trichophyton species and affects the foot. d. Tinea infections, or ringworm infections, are due to a pathogenic worm.

Why is the acid-fast stain clinically useful?

d a. It confirms that a single dose of antibiotics is enough to kill the bacteria. b. It identifies the causative agent of strep throat and scarlet fever. c. It identifies the causative agent of certain fungal infections. d. It identifies the causative agents of leprosy and tuberculosis. e. It confirms the results of the Gram stain.

How are L-forms different than Mycoplasma bacteria?

d a. L-forms have never had a cell wall. b. L-forms live inside animal cells. c. L-forms live inside plant cells. d. L-forms are resistant to certain environmental stresses like boiling and autoclaving. e. L-forms are susceptible to antibiotics that target the cell wall.

__________ are a collection of tubular structures, either septate or aseptate, which allow for growth in most fungi.

d a. Mycoses b. Conidiospores c. Spores d. Hyphae

What is the role of opsonins?

d a. They aid in the formation of the phagolysosome. b. They are present on the surface of phagocytes. c. They attract phagocytes to the location of infection. d. They create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader.

You have isolated a new eukaryotic organism which is unicellular and performs photosynthesis. The organism is most likely classified as a(n)

d a. animal. b. fungi-like protista. c. bacterium. d. plant-like protista. e. fungus.

All of the following are examples of inclusion bodies in prokaryotic cells except __________.

d a. carboxysomes b. glycogen granules c. magnetosomes d. endospores

To maintain a fluid plasma membrane in cold conditions, bacteria may modify their plasma membranes by

d a. concentrating their membrane phospholipids. b. diluting their membrane phospholipids. c. building their membrane phospholipids from cholesterol. d. incorporating short unsaturated fatty acids into their membrane phospholipids. e. incorporating long saturated fatty acids into their membrane phospholipids.

What is the order of the taxonomic hierarchy from least specific to most specific?

d a. domain, order, class, kingdom, phylum, species, family, genus b. species, genus, order, family, class, phylum, kingdom, domain c. class, order, phylum, kingdom, domain, genus, family, species d. domain, kingdom, phylum, class, order, family, genus, species e. domain, phylum, order, kingdom, class, family, genus, species

The scientific method starts with a(n)

d a. hypothesis. b. observation. c. prediction. d. question. e. proposal.

Protozoans are mainly grouped by their __________.

d a. mode of reproduction b. spore-forming potential c. nutritional requirements d. means of motility

Which type of cellular transport uses transport proteins and moves substances from an area of high concentration to an area of low concentration?

d a. phosphotransferase system b. primary active transport c. simple diffusion d. facilitated diffusion e. secondary active transport

Fungal infections are called

d a. sporgangia. b. coencytic. c. dimorphic. d. mycoses. e. basidium.

Microbes and humans have evolved a variety of ________ relationships, including ________ where microbes help the host.

d a. symbiotic; commensalism b. symbiotic; parasitism c. dynamic; commensalism d. symbiotic; mutualism e. commensal; mutualism

Phagocytosis is defined as

d a. the uptake of liquid material by a eukaryotic cell. b. the feeding of protozoans. c. cells of the immune system that ingest pathogens. d. the ingestion of solid material by a eukaryotic cell.

Which of the following is not an example of an inclusion body?

e a. Magnetosome b. Glycogen c. Poly-β-hydroxybutyrate d. Carboxysome e. Endosome

________ predict what happens, while ________ explain how and why something occurs.

e a. Observations; hypotheses b. Theories; laws c. Observations; conclusions d. Hypotheses; conclusions e. Laws; theories

Which of the following is true about ribosomes?

e a. Ribosomes build amino acids by linking together nucleic acids. b. Prokaryotic ribosomes are also easily differentiated from eukaryotic ribosomes based on chemical composition. c. Ribosomes are organelles made of RNA and carbohydrates. d. Antibiotics often take advantage of functional differences between prokaryotic and eukaryotic ribosomes. e. Prokaryotic ribosomes have a lower overall mass and diameter than eukaryotic ribosomes.

Unlike most flagella, periplasmic flagella:

e a. are located in the space between the plasma membrane and the peptidoglycan layer. b. move in a counter-clockwise direction. c. are made of proteins that stick into the cytoplasm for a better hold. d. move in a clockwise direction. e. are located in the space between the peptidoglycan layer and the outer membrane.

Which of the following cell shapes look like a comma?

e a. bacilli b. spirochetes c. coccobacilli d. stella e. vibrio

Which of the following does not enable bacterial endospores to be heat resistant?

e a. high amount of dipicolinic acid b. low water content c. exosporium d. spore coat e. peptidoglycan

The ability of certain bacterial cells to take on different cell shapes is known as

e a. meiosis. b. pyloric. c. pallidic. d. fission. e. pleomorphism.

Which of the following does not contribute to shifts in our normal microbiota?

e a. our general environment b. age c. hormonal changes d. diet e. proper hand-washing technique

Cell shape is determined by which of the following?

e a. the way cells divide b. the way cells move through their media c. whether or not the species uses a flagellum d. whether or not the species is pathogenic e. cell wall and cytoskeleton components