Biology 103 - Module 9 Study Guide
What are Koch's postulates?
A set of guidelines to demonstrate that a specific pathogen causes specific disease symptoms
Of the following, which group exhibits a diverse morphology, forming unicells, filaments, and sheets?
Green algae
Members of the alveolates are characterized by the presence of:
flattened vesicles under the plasma membrane.
Bacterial plasmids often have genes that code for genetic exchange or antibiotic resistance.
True
Foraminiferans are Rhizarians.
True
According to the progressive hypothesis, viruses may have originated as mobile genetic elements such as:
plasmids
Lactic-acid bacteria are used for:
producing sauerkraut.
Although bacteria lack membrane-bound organelles, such as chloroplasts and mitochondria, they can still perform the functions of these organelles by localizing certain metabolic enzymes on:
the plasma membrane.
Which Archaea have the ability to carry out a form of the Calvin cycle, capturing sunlight with bacteriorhodopsin?
Extreme halophiles
Which protist is responsible for late blight of potatoes, the cause of the Irish potato famine in the mid-19th century?
Phytophthora
Most protists are:
aquatic
Red algae, green algae, and land plants are collectively called _______________.
archaeplastids
What is a very small infective agent that consists of a core of nucleic acid and is dependent on a living host?
Virus
Prokaryotes divide using a process called________.
binary fission
The most common mode of reproduction in bacteria is:
binary fission.
Pseudopodia are used by Amoeba for ingesting food as well as for:
locomotion
How do bacteria move?
By means of a rotating flagella
Bacteriophages decrease food safety.
False
Mycoplasma
Lack cell walls
Which statement about euglenoids is FALSE?
They have a pellicle.
Which protist group contains the organism Trypanosoma, a colorless parasite that can cause African sleeping sickness?
Excavates
Within ciliates, what do the micronuclei control?
Reproduction
The body of a water mold is called a mycelium.
True
The dense cytoplasm of the prokaryote contains ribosomes and storage granules.
True
Diplomonads belong to which of the following group of eukaryotes?
Excavates
What is the purpose of sex pili?
To transmit DNA between bacteria
Parabasilids are excavates that lack functional mitochondria and lack a Golgi complex.
False
Viral proteins can damage host cells by which process?
Overwhelming the host cell with a large number of viruses
The immunodeficiency virus that causes acquired immunodeficiency syndrome is an enveloped virus.
True
What commercial product is derived from the processing of red algae?
Carrageenan
Which statement describes a temperate virus?
A temperate virus does not always destroy its host.
Which of the following statements is correct in the context of golden algae?
Are mostly unicellular, biflagellate freshwater and marine stramenopiles
What is the outcome of the process illustrated in the accompanying figure?
Two new genetically identical cells that differ genetically from what they were before
Humans have __________ pairs of chromosomes.
23
Which structure acts like a motor for the bacterial flagellum?
Basal body
_____________ are collared flagellates in the opisthokont clade, which also includes fungi and animals.
Choanoflagellates
Which protist groups consists of individuals who often have intracellular shells of interlocking plates?
Dinoflagellates
What is the correct unit of measurement for the size of most viruses?
Nanometers
Why is penicillin ineffective against gram-negative bacteria?
Penicillin cannot reach the thin peptidoglycan layer easily because it is protected by the bacteria's outer membrane.
Which has an unusual characteristic in that their circular DNA does not have genes for making the proteins needed to replicate and produce new viruses?
Polydnaviruses
How do retroviruses differ from other RNA viruses?
Retroviruses have reverse transcriptase instead of RNA-dependent RNA polymerase.
Which statement about radiolarians is FALSE?
They lack silica shells.
Which statement about viruses is FALSE?
Viruses can manufacture proteins.
Which of the following cause disease and often death?:
Viruses that have only a lytic cycle
Actinopods are mostly marine plankton rhizarians with long, filamentous cytoplasmic projections called __________.
axopods
The bacterium that causes botulism disease is harmless until it:
contains a certain prophage DNA.
Polydnaviruses are particles that consist of multiple circles of _______________ encased in capsid proteins and an envelope.
dsDNA
Herpesviruses
dsDNA: large complex enveloped virus; replicates in hot nucleus
The genome of most plant viruses consists of what kind of RNA?
ssRNA
At what stage of a lytic infection are phage components put together to make new viruses?
Assembly
Chlamydia
Lack peptidoglycan cell walls
Plasmids of bacteria often have genes involved in:
antibiotic resistance.
What is a prophage?
It is phage DNA that is integrated into bacterial DNA.
How do some bacteria respond to adverse environmental conditions?
Bacteria form endospores.
Which statement about biofilms is FALSE?
Biofilms are usually less than 2 μm thick.
Orthomyxoviruses
ssRNA that serves as template for mRNA synthesis; medium sized enveloped that often exhibit projecting spikes
What is the purpose of phage therapy?
To target specific bacteria in the body and destroy them
Which characteristic defines a virus?
Viruses cannot metabolize.
Which of the following are RNA viruses that have a DNA polymerase?
Retroviruses
Cellular slime molds and choanoflagellates
Unikonts
Retroviruses
ssRNA enveloped viruses; contains reverse transcriptase for transcription of RNA into DNA; two identical molecules ssRNA
Which statement about an F factor is FALSE?
It is found in recipient cells, not donor cells.
Red algae and green algae
Archaeplastids
Which of the following are rod-shaped bacteria?
Bacilli
Alveolates and stramenopiles
Chromalveolates
Dinoflagellates and water molds
Chromalveolates
Diplomonads and euglenoids
Excavates
Which was the first bacterium to be clearly identified as the cause of an infectious disease?
Bacillus anthracis, which causes anthrax
Among the protist groups below, which has organisms that typically move with two or more flagella?
Diplomonads
What are subviral agents that depend on co-infection of a host cell with a helper virus?
Satellites
What is vertical gene transfer?
The transmission of genetic material from parents to offspring during reproduction
Genomic deoxyribonucleic acid is chromosomal DNA.
True
Which eukaryotic organelles likely arose from symbiotic relationships between larger cells and bacteria?
Mitochondria and chloroplasts
A bacterium that uses the oxidation of inorganic compounds to provide energy for manufacturing nutritious organic compounds is a:
chemoautotroph
Trypanosomes and parabasalids
Excavates
Land plants are thought to have arisen most directly from a red algal ancestor.
False
Lytic reproductive cycles destroy host cells.
True
Togaviruses
ssRNA that can serve as mRNA; enveloped viruses
Bacteria protect themselves from bacteriophage infections by producing restriction enzymes that cut up foreign RNA of the phage.
False
Bacterial chemoautotrophs use organic chemicals as an energy source.
False
Gram-negative cell walls have an outer membrane that contains lipids and peptidoglycans.
False
Red tides are caused by red algae.
False
What is the translation of "pseudopodia," a characteristic of the amoebas?
False feet
Coralline forms of which group of protists are ecologically important in the formation of coral reefs?
Red algae
Forams and actinopods
Rhizarians
Some elongated fimbria are important in transferring DNA between bacteria.
True
The archaeplastids include the red algae and the green algae.
True
Most bacterial cells can keep from bursting in a hypotonic environment because of:
a rigid cell wall.
____________ are the largest and most complex of all algae.
brown algae
Where would you likely find Euryarchaeota bacteria?
Cow digestive tracts
Amoebozoans move by means of flagella.
False
Which protist group typically consists of amoeboid cells surrounded by a hard outer shell through which cytoplasmic projections extend?
Rhizarians
What does ssDNA stand for?
Single stranded DNA
A virus is a very small infective agent that consists of a core of nucleic acid and is dependent on a living host.
True
Dr. Stanley Prusiner concluded that the infective agent of CJD was not a virus because it was not sensitive to radiation, which mutates nucleic acids.
True
Fimbriae are only visible with the use of an electron microscope.
True
Horizontal gene transfer greatly contributes to the rapid evolution that takes place in prokaryotes.
True
Amoebozoans and opisthokonts
Unikonts
The most significant difference between archaea and bacteria is the:
absence of peptidoglycans in the cell walls of archaea.
Another name for horizontal gene transfer is____________.
lateral gene transfer
Viroids cause a variety of plant diseases and are composed only of:
strands of RNA.
Some bacteria avoid being phagocytized by a host's immune system by means of:
their capsule or slime layer.
Which protist group is characterized by having a micronucleus and a macronucleus?
Ciliates
Which algal group contains individuals that are typically unicellular and form siliceous shells?
Diatoms
Which of the following typically occurs all at once and results in rapid cell lysis?
Phage release
What are the viruses that attack bacteria?
Phages
Bacterial conjugation is related to____________.
horizontal gene transfer
At what stage of the lysogenic cycle would a prophage appear?
Integration
What type of conversion occurs when a bacterium carrying viral genes takes on new, atypical characteristics?
Lysogenic
Botox is the marketed version of the botulism exotoxin, used to treat muscle spasms and for cosmetic purposes.
True
Conjugation is the process by which one bacterium transfers genetic material to another through direct contact.
True
Retroviruses have a DNA polymerase called reverse transcriptase, which transcribes the RNA genome into a DNA intermediate.
True
Which statement about bioremediation is FALSE?
Very few species of bacteria are used to clean up various forms of pollution.
Which statement about bacteria is TRUE?
Bacteria are cellular and are sometimes classified as life forms.
How are viruses classified by the ICTV?
By their host range and other characteristics
Which protist group possess a crystalline rod in their flagella?
Euglenoids
Which protist clade (supergroup) is characterized by their greatly modified mitochondria?
Excavates
After an endospore forms, the cell membrane of the original cell lyses, releasing the endospore.
False
An emerging virus is one that is not new to a population or that is rapidly increasing in incidence.
False
Bacteriophages attach to the cell walls of bacteria by envelope proteins.
False
Coccolithophorids are marine members of the brown algae.
False
The nucleic acid core of the virus is not surrounded by a protein coat called a capsid.
False
When brown algae divide asexually, each new cell retains half of the original cell.
False
_________ secrete many-chambered tests with pores through which cytoplasmic projections extend to move and obtain food.
Forams
Ancestors of ____ may have possessed mitochondria, which were lost or reduced during evolutionary history.
Giardia
Which group of protists are unicellular, biflagellate stramenopiles that form a significant portion of the nanoplankton?
Golden algae
Streptococci, the bacteria responsible for strep throat infections, is classified within which group of bacteria?
Gram-negative bacteria
What are the small circles of DNA that exist within the bacterial cytoplasm in addition to the bacterial chromosome?
Plasmids
Which protist group are characterized by a multinucleate amoeboid-like feeding form?
Plasmodial slime molds
_______________ are those that have been almost eradicated and then suddenly recur, causing an epidemic.
Re-emerging viruses
Which protist group does not have flagellated cells?
Red algae
Which hypothesis asserts that viruses are remnants of cellular organisms and evolved from small cells that were parasites in larger cells?
Regressive hypothesis
Actinomycetes
Resemble fungi
_______________ are RNA viruses that have a DNA polymerase called reverse transcriptase, which transcribes the RNA genome into a DNA intermediate.
Retroviruses
Which statement best describes the composition of cell walls found in water molds?
Some individuals have cell walls of chitin, and others have cell walls of cellulose.
Who is credited with the discovery of prions as a new biological principle of infection?
Stanley Prusiner
What is a chain of round bacteria called?
Streptococci
Which are the symbiotic dinoflagellates, which live in the bodies of marine invertebrates such as corals?
Zooxanthellae
Before an animal cell's membrane fuses with a virus, the virus must first:
attach to a specific receptor on the plasma membrane of the host cell.
Papovaviruses
dsDNA: nonenveloped virus
The Archaea plasma membranes are made up of branched-chain hydrocarbons bounded to glycerol by:
ether linkages.
Small hairlike structures made up of protein on the surface of bacteria are called:
fimbriae
Peptidoglycan consists of:
sugars crosslinked with proteins.
Crenarchaeota are also called:
sulfur bacteria.
Unikonts also have a ____________ that has major evolutionary significance.
triple-gene fusion
Cells that have a single flagellum or are amoebas with no flagella are _________.
unikonts
Sexual reproduction can be grouped into how many distinct stages?
3
I am characterized by having a test and axopods. Who am I?
Actinopods
What is commensalism?
A relationship between individuals of two species in which one benefits and the other derives neither benefit nor harm
Which statement describes a virulent phage?
A virulent phage destroys bacteria.
______ are unicellular amoebozoa found in soil, fresh water, the ocean, and other organisms.
Amoebas
What is the protein coat of a virus called?
Capsid
___________ are amoebozoa with close affinities to amoebas and plasmodial slime molds.
Cellular slime molds
Cyanobacteria
Contain chlorophyll
Mycobacteria
Contain waxy cell wall
Which is the only prokaryote to carry on photosynthesis that generates oxygen?
Cyanobacteria
You find a unicellular organism that forms lobe-like pseudopodia. When you expose the cells to cAMP, they aggregate into a slug like structure. Based on this information, you correctly conclude that this organism is known as:
Dictyostelium discoideum.
Members of which group are known to form blooms known as red tides?
Dinoflagellates
Which of the following is NOT part of the Chromalveolates group of eukaryotes?
Euglenoids
Which of the following is the most common structure of a virus?
Icosahedron
A bacterial cell wall is made up of ______________.
N-acetyl glucosamine, N-acetyl muramic acid, and amino acids
Which is an anaerobic excavate that is an endosymbiont of animals?
Parabasilid
Which of the following are responsible for some very serious diseases, including Ebola hemorrhagic fever?
Pathogens
An example of an excavate that has a pellicle is Euglena.
True
Protists have various means of locomotion; they move by all of the following means EXCEPT:
by mycelium.
You find a protist that has a single flagellum surrounded by a collar of microvilli. You correctly conclude that this organism is a(n):
cellular slime mold
The DNA molecule is packaged into thread-like structures called ____________.
chromosomes
Some protists consist of a single cell with multiple nuclei. This condition is known as:
coenocytic