Bio 103 Module 5

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

What is the purpose of sex pili?

To transmit DNA between bacteria

Prokaryotes divide using a process called________.

binary fission

Lytic reproductive cycles destroy host cells. (T/F)

True

The body of a water mold is called a mycelium. (T/F)

True

The dense cytoplasm of the prokaryote contains ribosomes and storage granules. (T/F)

True

Which statement about bioremediation is FALSE?

Very few species of bacteria are used to clean up various forms of pollution.

According to the progressive hypothesis, viruses may have originated as mobile genetic elements such as:

plasmids.

Polydnaviruses are particles that consist of multiple circles of _______________ encased in capsid proteins and an envelope.

dsDNA

Unikonts also have a ____________ that has major evolutionary significance.

triple-gene fusion

Which statement describes a virulent phage?

A virulent phage destroys bacteria.

Which statement about bacteria is TRUE?

Bacteria are cellular and are sometimes classified as life forms.

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.

Land plants are thought to have arisen most directly from a red algal ancestor. (T/F)

False

Parabasilids are excavates that lack functional mitochondria and lack a Golgi complex. (T/F)

False

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.

The genome of most plant viruses consists of what kind of RNA?

ssRNA

What is a chain of round bacteria called?

Streptococci

A virus is a very small infective agent that consists of a core of nucleic acid and is dependent on a living host. (T/F)

True

The archaeplastids include the red algae and the green algae. (T/F)

True

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

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

When a virus penetrates the host plasma membrane and moves into the cytoplasm it is called:

penetration

Which protist groups consists of individuals who often have intracellular shells of interlocking plates?

Dinoflagellates

Among the protist groups below, which has organisms that typically move with two or more flagella?

Diplomonads

Which statement about an F factor is FALSE?

It is found in recipient cells, not donor cells.

Which is the only prokaryote to carry on photosynthesis that generates oxygen?

Cyanobacteria

Most protists are:

aquatic.

What are subviral agents that depend on co-infection of a host cell with a helper virus?

Satellites

Peptidoglycan consists of:

sugars crosslinked with proteins.

Humans have __________ pairs of chromosomes.

23

______ are unicellular amoebozoa found in soil, fresh water, the ocean, and other organisms.

Amoebas

Which of the following are rod-shaped bacteria?

Bacilli

How do bacteria move?

By means of a rotating flagella

___________ are amoebozoa with close affinities to amoebas and plasmodial slime molds.

Cellular slime molds

_____________ are collared flagellates in the opisthokont clade, which also includes fungi and animals.

Choanoflagellates

Match the group of bacteria with the corresponding description. Cyanobacteria Mycoplasma Actinomycetes Mycobacteria Chlamydia

Contain chlorophyll Lack cell walls Resemble fungi Contain waxy cell wall Lack peptidoglycan cell walls

Which of the following is NOT part of the Chromalveolates group of eukaryotes?

Euglenoids

Which protist group possess a crystalline rod in their flagella?

Euglenoids

Diplomonads belong to which of the following group of eukaryotes?

Excavates

After an endospore forms, the cell membrane of the original cell lyses, releasing the endospore. (T/F)

False

Amoebozoans move by means of flagella. (T/F)

False

Members of which protist group is one of the fossilized deposits in the unique geological formation of the White Cliffs of Dover?

Foraminiferans

_________ secrete many-chambered tests with pores through which cytoplasmic projections extend to move and obtain food.

Forams

What type of conversion occurs when a bacterium carrying viral genes takes on new, atypical characteristics?

Lysogenic

Which eukaryotic organelles likely arose from symbiotic relationships between larger cells and bacteria?

Mitochondria and chloroplasts

Viral proteins can damage host cells by which process?

Overwhelming the host cell with a large number of viruses

Which protist group does not have flagellated cells?

Red algae

Which protist group typically consists of amoeboid cells surrounded by a hard outer shell through which cytoplasmic projections extend?

Rhizarians

Which of the following is true for exotoxins?

The effect on the host is similar for all.

What is a very small infective agent that consists of a core of nucleic acid and is dependent on a living host?

Virus

The most common mode of reproduction in bacteria is:

binary fission.

Bacterial conjugation is related to____________.

horizontal gene transfer

What are Koch's postulates?

A set of guidelines to demonstrate that a specific pathogen causes specific disease symptoms

Which statement describes a temperate virus?

A temperate virus does not always destroy its host.

Which of the following is the most common structure of a virus?

Icosahedron

_______________ are those that have been almost eradicated and then suddenly recur, causing an epidemic.

Re-emerging viruses

Viroids cause a variety of plant diseases and are composed only of:

strands of RNA.

Sexual reproduction can be grouped into how many distinct stages?

3

Which was the first bacterium to be clearly identified as the cause of an infectious disease?

Bacillus anthracis, which causes anthrax

Bacteria protect themselves from bacteriophage infections by producing restriction enzymes that cut up foreign RNA of the phage. (T/F)

False

Bacteriophages attach to the cell walls of bacteria by envelope proteins. (T/F)

False

Bacteriophages decrease food safety. (T/F)

False

Coccolithophorids are marine members of the brown algae. (T/F)

False

Gram-negative cell walls have an outer membrane that contains lipids and peptidoglycans. (T/F)

False

What is the translation of "pseudopodia," a characteristic of the amoebas?

False feet

Which group of protists are unicellular, biflagellate stramenopiles that form a significant portion of the nanoplankton?

Golden algae

What is the correct unit of measurement for the size of most viruses?

Nanometers

Which of the following are responsible for some very serious diseases, including Ebola hemorrhagic fever?

Pathogens

Which hypothesis asserts that viruses are remnants of cellular organisms and evolved from small cells that were parasites in larger cells?

Regressive hypothesis

Within ciliates, what do the micronuclei control?

Reproduction

An example of an excavate that has a pellicle is Euglena. (T/F)

True

Bacterial plasmids often have genes that code for genetic exchange or antibiotic resistance. (T/F)

True

Horizontal gene transfer greatly contributes to the rapid evolution that takes place in prokaryotes. (T/F)

True

Retroviruses have a DNA polymerase called reverse transcriptase, which transcribes the RNA genome into a DNA intermediate. (T/F)

True

Some elongated fimbria are important in transferring DNA between bacteria. (T/F)

True

Which of the following cause disease and often death?:

Viruses that have only a lytic cycle

Most bacterial cells can keep from bursting in a hypotonic environment because of:

a rigid cell wall.

The most significant difference between archaea and bacteria is the:

absence of peptidoglycans in the cell walls of archaea.

____________ are the largest and most complex of all algae.

brown algae

Crenarchaeota are also called:

sulfur bacteria.

Who is credited with the discovery of prions as a new biological principle of infection?

Stanley Prusiner

How are viruses classified by the ICTV?

By their host range and other characteristics

What are the viruses that attack bacteria?

Phages

Which protist is responsible for late blight of potatoes, the cause of the Irish potato famine in the mid-19th century?

Phytophthora

What is vertical gene transfer?

The transmission of genetic material from parents to offspring during reproduction

Which statement about viruses is FALSE?

Viruses can manufacture proteins.

Protists have various means of locomotion; they move by all of the following means EXCEPT:

by mycelium.

The bacterium that causes botulism disease is harmless until it:

contains a certain prophage DNA.

Match the virus group with the corresponding nucleic acid description. Herpesviruses Papovaviruses Togaviruses Orthomyxoviruses Retroviruses

dsDNA: large complex enveloped virus; replicates in host nucleus dsDNA: nonenveloped virus ssRNA that can serve as mRNA ; enveloped viruses ssRNA that serves as template for mRNA synthesis; medium sized enveloped that often exhibit projecting spikes ssRNA enveloped viruses; contains reverse transcriptase for transcription of RNA into DNA; two identical molecules ssRNA

What is commensalism?

A relationship between individuals of two species in which one benefits and the other derives neither benefit nor harm

Which of the following statements is correct in the context of golden algae?

Are mostly unicellular, biflagellate freshwater and marine stramenopiles

At what stage of a lytic infection are phage components put together to make new viruses?

Assembly

Which structure acts like a motor for the bacterial flagellum?

Basal body

Where would you likely find Euryarchaeota bacteria?

Cow digestive tracts

Botox is the marketed version of the botulism exotoxin, used to treat muscle spasms and for cosmetic purposes. (T/F)

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. (T/F)

True

Fimbriae are only visible with the use of an electron microscope. (T/F)

True

The immunodeficiency virus that causes acquired immunodeficiency syndrome is an enveloped virus. (T/F)

True

The stramenopiles include water molds, diatoms, golden algae, and brown algae. (T/F)

True

Which characteristic defines a virus?

Viruses cannot metabolize.

Many green algae produce spores asexually by mitosis; if these spores have flagella and are motile, they are called __________.

zoopores

Which type of protist is responsible for malaria in humans, parasitic to both humans and mosquitoes?

Apicomplexans

_________ are parasites that produce sporozoites and are nonmotile.

Apicomplexans

Which protist group is characterized by having a micronucleus and a macronucleus?

Ciliates

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.

Match the supergroup with the representative clade. Diplomonads and euglenoids Trypanosomes and parabasalids Alveolates and stramenopiles Dinoflagellates and water molds Forams and actinopods Red algae and green algae Cellular slime molds and choanoflagellates Amoebozoans and opisthokonts

Excavates Excavates Chromalveolates Chromalveolates Rhizarians Archaeplastids Unikonts Unikonts

An emerging virus is one that is not new to a population or that is rapidly increasing in incidence. (T/F)

False

Of the following, which group exhibits a diverse morphology, forming unicells, filaments, and sheets?

Green algae

What is a prophage?

It is phage DNA that is integrated into bacterial DNA.

Which of the following typically occurs all at once and results in rapid cell lysis?

Phage release

Coralline forms of which group of protists are ecologically important in the formation of coral reefs?

Red algae

Which of the following are RNA viruses that have a DNA polymerase?

Retroviruses

_______________ are RNA viruses that have a DNA polymerase called reverse transcriptase, which transcribes the RNA genome into a DNA intermediate.

Retroviruses

How do retroviruses differ from other RNA viruses?

Retroviruses have reverse transcriptase instead of RNA-dependent RNA polymerase.

Which are the symbiotic dinoflagellates, which live in the bodies of marine invertebrates such as corals?

Zooxanthellae

Plasmids of bacteria often have genes involved in:

antibiotic resistance.

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.

Another name for horizontal gene transfer is____________.

lateral gene transfer

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.