Chapter 12
Which component is characteristic of the cell wall of Fungi but is absent in the cell wall of Bacteria?
Chitin
Which fungal species is known as a major "model organism" in research and is critically important in industrial fermentation processes for making bread, beer, and wine?
Saccharomyces cerevisiae
What are viruses scientifically categorized as?
What is the term used to describe a complete, fully developed viral particle outside of a host cell?
Virion
What is the unit for measuring bacteriophage virus population numbers?
Plaque forming units
The total fungal body (thallus), which consists of a mass of hyphae filaments, is scientifically termed what?
Mycelium
A common parasitic protozoan infection that causes watery diarrhea and is the leading cause of waterborne disease among humans in the United States, especially protected by an outer shell tolerant to chlorine disinfection, is caused by:
Cryptosporidium
What structural component of a virus is composed of protein subunits called capsomeres?
Capsid
What is the term used to describe a complete, fully developed viral particle outside of a host cell?
Envelope
According to scientific estimates, the sheer volume of tailed bacteriophages (≈10^31) on Earth, when aligned head to tail (each measuring 200 nm), would cover a total distance equivalent to approximately how many light years?
200 million light years (2×10^8 light years)
A dimorphic fungus is characterized by exhibiting moldlike growth at a temperature of 25∘C. What type of growth would this fungus display at 37∘C?
Yeastlike growth
In addition to consuming undercooked, contaminated meat, a major route of human transmission for the obligate intracellular parasite Toxoplasma gondii involves contact with:
For viruses that possess an envelope, the carbohydrate-protein complexes that project from the surface and are used for attachment are called:
Spikes
In the lysogenic cycle of a bacteriophage, the incorporated phage DNA within the host cell chromosome is specifically termed a:
The SARS-CoV-2 virus particle initiates entry into the host cell (like a lung cell) by binding its Spike protein to which specific host receptor?
ACE2 receptor protein
A primary and highly significant role of planktonic algae in nature is their contribution to global oxygen production. Approximately what percentage of Earth's oxygen is produced by these organisms?
80%
Flat, segmented worms that live in the intestines and whose infection in humans (cestodiasis) is often caused by eating undercooked meat (like pork or beef) are known as:
Tapeworms (Cestodes)
During the biosynthesis of most DNA viruses, viral DNA replication and protein assembly generally occur in which cellular location?
The nucleus of the host cell
The Baltimore classification system categorizes viruses into seven groups based primarily on how they ultimately achieve the synthesis of which essential nucleic acid molecule?
mRNA
The concept of Cellular Tropism explains why the HIV virus normally infects which specific cell type within the host, but not neurons?
Macrophages
What are unicellular algae with silica walls?
Diatoms
How do cellular slime molds ingest bacteria?
Phagocytosis
The infectious agent responsible for diseases like Creutzfeldt-Jakob disease and scrapie in sheep, which is reduced by protease treatment but not by radiation, is a:
Prion (or proteinaceous infectious particle)
The introduction of viral DNA into the host chromosome, particularly characteristic of retroviruses, where the DNA remains integrated and replicates with the host cell DNA, forms a structure known as a:
Provirus
The genome of Influenza A viruses is unique among common human pathogens because it is typically composed of how many segments of negative-sense RNA?
7 or 8 segments