biology module 9 exam
What are Koch's postulates?
A set of guidelines to demonstrate that a specific pathogen causes specific disease symptoms
The nucleic acid core of the virus is not surrounded by a protein coat called a capsid.
False
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.
Lytic reproductive cycles destroy host cells.
True
Polydnaviruses are particles that consist of multiple circles of _______________ encased in capsid proteins and an envelope.
dsDNA
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.
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
Which statement about bacteria is TRUE?
Bacteria are cellular and are sometimes classified as life forms.
Gram-negative cell walls have an outer membrane that contains lipids and peptidoglycans.
False
Land plants are thought to have arisen most directly from a red algal ancestor.
False
Which of the following is the most common structure of a virus?
Icosahedron
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 of the following typically occurs all at once and results in rapid cell lysis?
Phage release
The genome of most plant viruses consists of what kind of RNA?
ssRNA
Viroids cause a variety of plant diseases and are composed only of:
strands of RNA.
Peptidoglycan consists of:
sugars crosslinked with proteins.
What is vertical gene transfer?
The transmission of genetic material from parents to offspring during reproduction
What is the purpose of phage therapy?
To target specific bacteria in the body and destroy them
What is the purpose of sex pili?
To transmit DNA between bacteria
Genomic deoxyribonucleic acid is chromosomal DNA.
True
Retroviruses have a DNA polymerase called reverse transcriptase, which transcribes the RNA genome into a DNA intermediate.
True
Which are the symbiotic dinoflagellates, which live in the bodies of marine invertebrates such as corals?
Zooxanthellae
Red algae, green algae, and land plants are collectively called
archaeplastids
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.
Small hairlike structures made up of protein on the surface of bacteria are called:
fimbriae.
Pseudopodia are used by Amoeba for ingesting food as well as for:
locomotion.
When a virus penetrates the host plasma membrane and moves into the cytoplasm it is called:
penetration.
Which of the following statements is correct in the context of golden algae
Are mostly unicellular, biflagellate freshwater and marine stramenopiles
How are viruses classified by the ICTV?
By their host range and other characteristics
Which is the only prokaryote to carry on photosynthesis that generates oxygen?
Cyanobacteria
Horizontal gene transfer greatly contributes to the rapid evolution that takes place in prokaryotes.
True
The body of a water mold is called a mycelium.
True
What is commensalism?
A relationship between individuals of two species in which one benefits and the other derives neither benefit nor harm
Which type of protist is responsible for malaria in humans, parasitic to both humans and mosquitoes?
Apicomplexans
At what stage of a lytic infection are phage components put together to make new viruses?
Assembly
Which was the first bacterium to be clearly identified as the cause of an infectious disease?
Bacillus anthracis, which causes anthrax
What is the protein coat of a virus called?
Capsid
Where would you likely find Euryarchaeota bacteria
Cow digestive tracts
Where would you likely find Euryarchaeota bacteria?
Cow digestive tracts
Which algal group contains individuals that are typically unicellular and form siliceous shells?
Diatoms
Which protist clade (supergroup) is characterized by their greatly modified mitochondria?
Excavates
Members of which protist group is one of the fossilized deposits in the unique geological formation of the White Cliffs of Dover?
Foraminiferans
What is a prophage?
It is phage DNA that is integrated into bacterial DNA.
Which of the following are responsible for some very serious diseases, including Ebola hemorrhagic fever?
Pathogens
What are subviral agents that depend on co-infection of a host cell with a helper virus?
Satellites
What does ssDNA stand for?
Single stranded DNA
Which statement about radiolarians is FALSE?
They lack silica shells.
What is a very small infective agent that consists of a core of nucleic acid and is dependent on a living host?
Virus
Which statement about viruses is FALSE?
Viruses can manufacture proteins.
Which characteristic defines a virus?
Viruses cannot metabolize.
Which of the following cause disease and often death?:
Viruses that have only a lytic cycle
The DNA molecule is packaged into thread-like structures called ____________.
chromosomes
Another name for horizontal gene transfer is____________.
lateral gene transfer
Within ciliates, what do the micronuclei control?
Reproduction
How do bacteria move?
By means of a rotating flagella
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
Which statement describes a virulent phage?
A virulent phage destroys bacteria.
Which of the following statements is correct in the context of golden algae?
Are mostly unicellular, biflagellate freshwater and marine stramenopiles
____________ are collared flagellates in the opisthokont clade, which also includes fungi and animals.
Choanoflagellates
Which protist group is characterized by having a micronucleus and a macronucleus?
Ciliates
Among the protist groups below, which has organisms that typically move with two or more flagella?
Diplomonads
Amoebozoans move by means of flagella.
False
An emerging virus is one that is not new to a population or that is rapidly increasing in incidence
False
Coccolithophorids are marine members of the brown algae.
False
Land plants are thought to have arisen most directly from a red algal ancestor
False
Red tides are caused by red algae.
False
Which group of protists are unicellular, biflagellate stramenopiles that form a significant portion of the nanoplankton?
Golden algae
Which eukaryotic organelles likely arose from symbiotic relationships between larger cells and bacteria?
Mitochondria and chloroplasts
Which protist is responsible for late blight of potatoes, the cause of the Irish potato famine in the mid-19th century?
Phytophthora
Bacterial plasmids often have genes that code for genetic exchange or antibiotic resistance.
True
Most bacterial cells can keep from bursting in a hypotonic environment because of
a rigid cell wall.
Most bacterial cells can keep from bursting in a hypotonic environment because of:
a rigid cell wall.
Lactic-acid bacteria are used for:
producing sauerkraut.
