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