BIOL 1011 Mastering Microbiology Test 1

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

Gram-negative bacteria have an outer membrane as part of their cell wall.

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

Gram-positive

Which of the following pathogen agents is multicellular?

Helminths

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

Hyphae

Which pairing of organism and the chemical component of its cell wall is matched incorrectly?

Animals: cholesterol

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?

L-form bacteria

Amoeboid protozoans

May exist in the environment encased in a tough protective layer called a cyst.

Protozoans are mainly grouped by their __________.

Means of motility

_____________ is a type of sexual reproduction that occurs in eukaryotes and results in four genetically unique haploid daughter cells.

Meiosis

Which of the following is an example of a reemerging disease?

Mumps, once nearly eliminated, has increased in prevalence due to under-vaccination in industrialized countries.

Fungal infections are called

Mycoses

The genetic material of bacteria can be found in the

Nucleoid

Prokaryotic cells house a single circular chromosome in their __________.

Nucleoid region

Why are most prokaryotic cells small?

Nutrient diffusion is most efficient for smaller cells

Candida albicans is part of our normal oral flora. Under certain conditions, it can overgrow, leading to oral thrush. Typically, infections are seen in individuals who are immunocompromised, such as newborns or individuals who may have recently taken antibacterial medications. This type of pathogen is classified as which of the following?

Opportunistic, endogenous pathogen

The 1918 influenza virus killed more individuals worldwide than World War One. It is estimated that between twenty and forty percent of the world's population across continents had become infected with the virus, leading to 50 million deaths. The 1918 influenza would best be described as which of the following?

Pandemic

What is a widespread disease outbreak that spreads to numerous countries during a specific time frame

Pandemic

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

Peptidoglycan

Which feature is not found in protozoans?

Performs photosynthesis

Which of the following allows the spirochete Borrelia burgdorferi to move in a corkscrew motion?

Periplasmic flagellum

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

Peritrichous flagella

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

Pili

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

Plant-like protista

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

Pleamorphism

Choose the statement which best defines a pleomorphic organism.

Pleomorphic organisms can take on different forms, which enhances their survival and transmission to a human host.

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

The cell will take on water and may lyse if its cell wall is damaged.

Which of the following statements describes eukaryotic cells?

They contain membrane-bound organelles such as a nucleus

Which of the following is/are an example of a healthcare-acquired infection?

1. A hospitalized patient develops Staphylococcal sepsis after a nurse transmits the pathogen to the patient while changing wound dressing. 2. A patient develops pneumonia after using a contaminated ventilator at an outpatient care facility. 3. A nursing home patient develops a urinary tract infection from a contaminated catheter in a nursing home facility.

Which of the following is/are primary reason(s) why healthcare settings are hot zones for antibiotic-resistant pathogens?

1. Abundance of susceptible, immunocompromised patients 2. Extensive use of antibiotics among patients

Choose the true statement(s) about binary fission in prokaryotic cells.

1. Binary fission results in offspring, which are genetically identical to the parent cell. 2. Binary fission is a type of asexual reproduction that is simpler than mitosis. 3. Binary fission frequency differs between species and is affected by environmental conditions.

Choose the true statement(s) about prokaryotic external appendages.

1. Flagella allow for motility. 2. Pili allow for adhesion, movement, and aid in gene transfer through conjugation. 3. The glycocalyx promotes adhesion and interferes with phagocytosis.

Choose the true statement(s) concerning the eukaryotic glycocalyx.

1. It plays a role in cell communications 2. It promotes or prevents cell adhesion where appropriate

Choose the true statement(s) about prokaryotic cells.

1. Most of a prokaryote's nutrients are obtained through diffusion. 2. All prokaryotes are unicellular organisms. 3. All prokaryotes lack a membrane-bound nucleus and organelles.

Choose the true statement(s) about protists.

1. Protists can be photosynthetic or heterotrophic. 2. The term protozoan describes animal-like protists but is not a true taxonomic ranking.

Choose the true statement(s) about spore-forming bacteria.

1. Spore-forming bacteria, such as Clostridium, contain heat- and chemical-resistant layers around the spore coat, making them difficult to destroy. 2. Disinfectants such as bleach are sporicidal and are effective in destroying spores.

Choose the true statement(s) about the prokaryotic cytoskeleton.

1. The prokaryotic cytoskeleton directs construction of a rigid cell wall. 2. The prokaryotic cytoskeleton provides general organization of the cytoplasm.

Hyphae are

A collection of tubular structures that result from fungal growth.

How is a reemerging pathogen different from an emerging pathogen?

A reemerging pathogen is an infectious agent that was under control due to prevention or treatment strategies and is now resurfacing.

Cell shape is determined by which of the following?

Cell wall and cytoskeleton components

Which of the following is an example of a direct contact transmission?

An individual contracts rabies after being bitten by a rabid raccoon

Why aren't Archaea discussed as much as bacteria?

Archaea haven't been lined to human diseases

If you had to choose to be either a chronic carrier or an asymptomatic carrier, which would you choose any why?

Asymptomatic carrier because I wouldn't experience any symptoms

Which of the following is an endogenous source of infection?

Bacteria from the skin entering a surgical infection

How does the cell wall of bacteria and archaea differ?

Bacteria use peptidoglycan.

It is called a ________ vector when the vector organism has a role in the pathogen's life cycle.

Biological

The primary difference between a biological and a mechanical vector is that:

Biological vectors play a role in the pathogen's life cycle, whereas a mechanical vector spreads disease without being integral to a pathogen's life cycle.

Membrane proteins perform all of the following functions except

Blocks

Most prokaryotic cells reproduce

By binary fission

Patients infected with Herpes simplex virus-1, the causative agent of fever blisters, go through periods of viral inactivity (where no active oral cankers appear) and outbreaks (where fever blisters are present). This type of individual is best defined as a(n) _______________.

Chronic carrier

Choose the true statement about cilia and flagella.

Cilia and flagella are surrounded by a membrane and sprout from centrioles.

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

Clusters of bacilli form a Staph arrangement.

A chemical compound which specifically disrupts the 9+2 microtubule arrangement would be a potential drug candidate as a(n)

Contraceptive drug disabling motility of human sperm.

A similarity between mitosis and meiosis is

Copying DNA before the cell divides

Chapter 9

Diseases

What is the definition of a true pathogen?

Does not require a weakened host to cause disease

You encounter a cell that has a cell wall. Imagine you can ask only one other question about the organism, and that based on the answer you get, you must classify the organism as either a bacteria, archaea, fungus, or animal. Which question would you ask?

Does the organism make ergosterol?

What is routinely detected in a population or region?

Endemic infections

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

Endospores

Which of the following is true about endospores?

Endospores are highly resistant to environmental stress

Chapter 4

Eukaryotes

Which of the following statements is false about eukaryotes?

Eukaryotes have a much simpler genetic makeup than prokaryotic cells.

T/F: A bacteria's DNA can be found in the nucleus of the cell.

False

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

False

T/F: Bacterial plasma membranes differ from eukaryotic plasma membranes in that bacterial membranes always contain cholesterol while eukaryotic membranes rarely do.

False

T/F: Binary fission, mitosis, and meiosis all produce genetically identical daughter cells.

False

T/F: Chronic diseases have a rapid onset and progression.

False

T/F: The acute phase of an infectious disease, when the pathogen levels are the highest, is the most contagious stage of any pathogen.

False

T/F: The source of an infectious agent is the animate or inanimate habitat where the pathogen is naturally found.

False

The four groups of protozoans are grouped by their mode of reproduction.

False

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

Fimbriae

Which does not describe eukaryotic flagella?

Flagellin protein

You have isolated a new organism which has eukaryotic cells, is multicellular, grows as hyphae, does not perform photosynthesis, and has a cell wall. This organism most likely belongs to which kingdom?

Fungi

Which of the following is a common healthcare-acquired infection?

Gastrointestinal infection caused by Clostridium difficile

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

Gastrointestinal tract

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

Glycocalyx

What is the order of the five stages of infectious disease?

Incubation period, prodromal phase, acute phase, period of decline, convalescent phase

Choose the false statement regarding prokaryotic plasma membranes.

Ions and large polar substances can diffuse through the plasma membrane without assistance.

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

It undergoes plasmolysis

You encounter a motile cell that has a cell wall containing xylan. What is the most likely taxonomic kingdom for the organism?

Kingdom Protista

Chapter 3

Prokaryotes

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

Prokaryotes have a ribosome with a 70S sedimentation rate

Which of the following is true about ribosomes?

Prokaryotic ribosomes have a lower overall mass and diameter than eukaryotic ribosomes

Choose the false statement(s). The four kingdoms of eukaryotes each include members that may conduct sexual and/or asexual reproduction. Protists are strictly unicellular. The four kingdoms of eukaryotes include Animalia, Plantae, Fungi, and Protista. Kingdom Fungi includes unicellular and multicellular organisms.

Protists are strictly unicellular

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

Protozoa

Which grouping of parasitic helminths includes hookworms?

Roundworms

Bacillus cereus is naturally found in the soil. B. cereus is known to contaminate rice, which, if undercooked and ingested, can lead to gastroenteritis. In this example, the reservoir for B. cereus is the ________, and the source of infection is the ___________.

Soil; rice

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

Streptococci

Choose the true statement about the Domain Bacteria.

The Domain Bacteria is made up of prokaryotes and likely originated 3.8 billion years ago.

Which of the following is false about the bacterial cytoskeleton?

The bacterial cytoskeleton contains actin and tubulin proteins

The role of the glycocalyx in eukaryotic cells may include

Tissue development

T/F: According the endosymbiont theory we can reason that the merging event that led to the mitochondria occurred before the merging event that led to the chloroplast because all eukaryotic cells which have chloroplasts also have mitochondria, but all cells that have mitochondria do not necessarily have chloroplasts.

True

T/F: Bacteria that have flagella at both poles of the cell are described as amphitrichous.

True

T/F: Gram-positive bacteria stain purple when the Gram stain is complete.

True

T/F: Spirochetes move in a corkscrew-rotary motion due to a specialized periplasmic flagellum.

True

T/F: The kingdom Protista contains species which have plant-like features, others which contain animal-like features, and still others that contain fungal-like features. This is because scientists do not have a set of standard features by which to group them.

True

T/F: Zoonotic diseases are spread from animals to humans.

True

Where are cilia found in the human body?

Upper respiratory tract

Which of the following is an indirect infectious disease transmission mode?

Vehicle

Which of the following cell shapes look like a comma?

Vibrio

Your patient comes to you with typical signs of pneumonia: high fever, shortness of breath, and persistent cough. Several tests are performed to determine the causative agent of disease. You observe that you are unable to culture the microbe using standard microbiological media (such as nutrient agar). Furthermore, use of fluorescent probes reveals that the pathogen has a genome composed of stranded RNA. Which of the following microorganisms are you most likely observing?

Virus