UNIT 1

Select those structures that are found in a gram-positive cell envelope.

Thick layer of peptidoglycan Cell membrane Teichoic acids Lipoteichoic acids

Asymmetrical spacing of the backbones of the DNA double helix generates major and minor grooves.

True

Most microorganisms that are found in and on the humans do not cause harm and can sometimes benefit the host

True

Which of the following is an acellular infectious agent?

VIRUS

Select the items that would be found in bacterial cytoplasm.

Water Ribosomes Plasmids Bacterial Chromosomes Bacterial Endospores Enzymes inclusion bodies

A vegetative cell is _____

a metabolically active cell

which of the following is not useful to determine whether a clinical isolate is a bacterium, fungus, or protozoan?

a.size b. if it has a cell wall c.if it can form protective structures

Select all of the characteristics of eukaryotic flagella that distinguish them from bacterial flagella.

b) whip back and forth c) consist of a 9 + 2 microtubule arrangementd) e) 200 nm in diamete

Mitochondria likely originated from

bacteria

Which of the following processes can be the result of human manipulation of microbial genes?

bioremediation

The two major types of helminths based on body type are the _______, which include the tapeworms, and the ________, which are also known as nematodes.

flatworms;roundworms

Which of these organisms has the best potential to survive in extreme environments?

fungi

Long, threadlike fungal cells are called _________, and an intertwined mass of these cells is called a _________.

hyphae; mycelium

a vegetative cell is a ____

metabolically active cell

When spore formation begins, the vegetative cell is referred to as the ________.

mother cell

4. Microenvironments are created within the biofilm based on _______.

pH gradient nutrient concentration oxygen gradient --All of the above are correct

The cortex is formed from _____.

peptidoglycan

3. Which of the following is considered an "adverse condition" by most bacteria?

ph=4

Select the components of DNA and RNA to test your understanding of nucleic acid composition.

phosphate ribose and deoxyribose nitrogenous bases

The correct structure of DNA components can be presented as ________.

phosphate-suger-base

which of the following is a macromolecule that assembles into bilayers?

phospholipid

Select characteristics exhibited by BOTH bacterial and eukaryotic cytoplasmic membranes.

phospholipid bilayer embedded proteins selectively permeable barrier transport systems

In the final step of spore formation a _____ coat forms around the cortex.

protein

ribosomes are the site of

protein synthesis

Which of these groups causes the most casualties on an annual basis globally?

protozoa

Choose the statement that best describes the role of mitochondria.

provide cell with energy through cell respiration

The three structures utilized for locomotion by protozoa are flagella, cilia, and ________.

psuedopods

alpha helices and beta pleated sheets are examples of _____protein structure.

secondary

protein structure that would be disrupted by heat or solvent changes that would disrupt hydrogen bonding

secondary, tertiary, quaternary

Fungi produce which structures for reproduction and multiplication?

spores

The developing spore is surrounded by:

the membrane of the mother cell

Choose the statement or characteristic that best describes the Woese-Fox taxonomic system to test your understanding of taxonomy

three distinct cell lines called domains

A spirochete moves in a screwlike manner that is mediated by axial fibrils located in the cell's periplasmic space.

true

Despite the lack of a membrane-bound nucleus, bacteria and archaea are cells with a complex organizational structure.

true

Many chronic conditions are found to be associated with microbial agents.

true

Members of the same species share many more characteristics compared to those shared by members of the same kingdom.

true

Mycoplasma pneumoniae lacks a cell wall and are pleomorphic in shape.

true

Spirillum is a genus of spiral-shaped bacteria that move by flagella.

true

The most important outcome of polypeptide intra-chain bonding and folding is the unique shape of the protein. True or False

true

True or False: Encapsulated bacterial cells generally have greater pathogenicity.

true

Viruses are not classified in any of Whittaker's five kingdoms.

true

biofilms typically do not develop on healthy tissue

true

When is sporulation initiated by spore-forming bacteria?

when nutrients are depleted or conditions become adverse

Select characteristics exhibited by the glycocalyx of eukaryotic cells.

*Outermost surface of the cell *composed of polysaccharide *means of adhering to other cells and surfaces *signal reception

3. The production of which substance leads to thickening of the biofilm over time?

Exopolymer

select the structures that enable bacteria to be motile

Flagella Axial Filaments

Select the structures that are possessed by some, but not all bacteria.

Flagella Endospores Pili Fimbriae Glycocalyx

Two different kinds of appendages may be found on eukaryotic cells that enable them to move. ________ are long slender locomotor appendages that are usually single and few in number, whereas ________ are appendages which are numerous and short.

Flagella and cilia

Which of the following DNA molecules is the most stable?

GCGTGCAC CGCACGTG

Select the nitrogenous bases found in nucleotides that make up DNA.

Guanine Thymine Adenine Cytosine

Select the nitrogenous bases found in nucleotides that make up RNA.

Guanine Uracil Adenine Cytosine

Select the terms which describe various members of the archaea.

Hyperthermophiles Methanogens Acidophiles Extreme halophiles Extremophiles

Major groups of microorganisms studied by microbiologists are...

- bacteria - helminths - algae - fungi - viruses - archaea - protozoa

Select all answers that are roles played by microorganisms in our environment.

- carry out photosynthesis - biological decomposition - nutrient recycling

Select statements that apply to the theory of evolution to test your understanding of evolution.

- has undergone years of testing - has not been disproven - is a well-established natural phenomenon

Choose the response(s) that pertain to the relative burden of human infectious diseases in the world today.

- nearly 2000 microbes can cause human disease today - Many diseases that used to be considered noninfectious probably do involve microbial infection based upon current studies. - There is an increase in microbes that are resistant to drugs today.

Select the organisms that typically have cell walls.

-FUNGI -algae -plants

Select those activities of fungi considered detrimental from a human perspective.

-Produce toxins such as aflatoxin -Cause decomposition of fresh produce -Cause disease in plants and animals -Contribute to allergies

top causes of death by disease

-Respiratory illness is the leading cause of death by an infectious disease both in the United States and worldwide -Across the globe, influenza and pneumonia will kill almost half as many individuals as heart disease -In the United States, the percentage of deaths by infectious disease is lower than the percentage of deaths by infectious disease worldwide.

relative burden of infectious diseases in the world today

1. nearly 2,000 microbes can cause human disease today 2. many diseases that used to be considered noninfectious probably do involve microbial infection based upon current studies 3.there is an increase in microbes that are resistant to drugs today

Which of the following is a characteristic of double-stranded DNA?

2 nanometers in width, 10 base pairs per turn, and 0.34 nanometers per full turn

Select the main groups of macromolecules found in living things.

A. nucleic acids D. lipids E. proteins F. carbohydrates

Select the components of ATP

Adenine Ribose Phosphate

Select all of the groups on this list that contain eukaryotic microorganisms.

Algae Protozoa Helminths Fungi

Select characteristics exhibited by all bacteria.

Chromosomes Ribosomes Cell Membrane

the Golgi apparatus

Modifies, sorts, and packages proteins

Select those structures that are found in a gram-negative cell envelope

Outer membrane Periplasmic space Cell membrane Lipopolysaccharide Thin layer of peptidoglycan

DNA leads to RNA, which can lead to the creation of ________.

PROTEINS

Chloroplasts are the site of ________ and are located in plants and plantlike organisms called ________.

Photosynthesis, algae

Please select the characteristics exhibited by most protozoans. Check all that apply.

Protozoa are a very diverse group of unicellular eukaryotic microorganisms. The diversity of the protozoa complicate the classification and taxonomy of this group. They are informally grouped together because most share the following characteristics: motility, unicellularity, presence of a nucleus and a variety of other organelles (eukaryotic), heterotrophic nutrition, and a size range from 3 - 300 µm.

Choose the term that best describes the role of protozoan cysts.

Protozoan cysts are a survival form that allows them to survive adverse environmental conditions between hosts.

Which of the following choices is a correct way to denote the binomial name of a microorganism?

Staphylococcus aureus (both italicized)

T/F: most microorganisms that are found in and on humans do not cause harm and can sometimes benefit the host.

TRUEEE

Choose the term that describes the formal system of identifying, arranging, and naming organisms.

Taxonomy

Disulfide bonds are involved in maintaining ________ protein structure as well as the ________ level of protein structure exhibited by complex proteins such as antibodies.

Tertiary; Quaternary

Choose the most accurate description of a typical helminth lifestyle.

The helminth reproduces sexually and spends most of its life in either a single animal host or a series of animal hosts.

BioTechnology

The term used to describe the broad field of science that involves human manipulation of microbes for use in industrial processes is ________.

Which of the following surfaces have nutrients available that encourage the development of biofilms? a. moist abiotic surfacesb. dry abiotic surfacesc. moist abiotic surfaces and biotic surfaces such as plant and animal tissued. biotic surfaces such as plant and animal tissue

c. moist abiotic surfaces and biotic surfaces such as plant and animal tissue

In the next phase of spore formation, _____ enters the cortex and _____ leaves the cortex.

calcium, water

biofilms

can lead to systemic infections

Select all areas that comprise the main aspects of the science of taxonomy.

classification nomenclature identification

Select characteristics exhibited by all cells.

cytoplasmic membrane DNA Ribosomes

Choose the statement that correctly describes the major difference between bacterial and eukaryotic ribosomes.

differ in size

Analyze the following statements, and select those that correctly reflect the characteristics of archaea.

extreme halophiles are not only tolerant to high salt levels; they require it to grow metabolically, archaea are the most diverse group of organisms on the planet, surviving in extreme conditions such as extreme heat , high salt levels, extreme pH, and high pressure

4. True or False: The thinner peptidoglycan layer of gram-positive bacteria allows the crystal-violet-iodine complex to leave the cell.

false

Gram-positive bacteria have flagella with four basal body rings, while those of gram-negative bacteria have only two.

false

If a hypothesis is accepted, then the findings become a scientific law.

false

Nucleic acids have primary, secondary, tertiary, and quaternary levels of organization.

false

T/F - Current evidence indicates that bacteria and archaea existed on earth for approximately 2 billion years before eukaryotes appeared

false

The acceptance or rejection of a hypothesis is based on a series of educated guesses and opinions. Once the opinion is widely accepted it becomes a theory.

false

The names of the three proposed domains are: Bacteria, Protista, Eukarya. T or F?

false

True or False: Endospores function in the reproduction of bacterial genera such as Bacillus and Clostridium.

false

True or False: Most bacterial genera are capable of forming endospores.

false

True or False: When a spore germinates, it gives rise to two vegetative cells.

false

True or False: When the bacterial glycocalyx is easily removed, it is called a capsule.

false

a scientist studying helminths is working with bacteria

false

biofilms are often more sensitive to antibiotics

false

When a bacterial endospore germinates, it develops into multiple vegetative cells assuring reproductive success

false (endospores are not reproductive structures. One vegetative cell will form one endospore. When the spore is released, the vegetative cell(sporangium) is lysed. When the endospore germinates, it will form one vegetative cell.

Which of the following structures leads to reversible binding of bacterial cells to a surface?

fimbriae and flagella