Exam 2 iClickers Flashcards
- Why are viruses considered acellular?
A. They do not have a nucleus
B. They do not have a phospholipid-based membrane
C. The cannot replicate independently
D. They do not have genetic material
C. The cannot replicate independently
- The plaque assay for counting viruses will measure:
A. Only infectious viral particles
B. All viruses, including infectious and non-infectious particles
C. Approximately 10% of all viruses present
D. The number of infected host cells
A. Only infectious viral particles
- What is the fundamental premise of the regressive hypothesis for the origin of viruses?
A. Viruses evolved at the same time as their host cells
B. Host cells gained the ability to replicate semi-autonomously and transmit their nucleic acid
genomes
C. Viruses were once independent cells that became dependent on host cells
D. None of these choices
C. Viruses were once independent cells that became dependent on host cells
- Which of the following is not a question concerning viral evolution?
A. What is the origin of viruses?
B. How old are viruses?
C. Do viruses affect cellular evolution?
D. Are viruses monophyletic?
C. Do viruses affect cellular evolution?
- What is the fundamental premise of the progressive hypothesis for the origin of viruses?
A. Viruses evolved at the same time as their host cells
B. Hosts gained the ability to replicate semi-autonomously and transmit their nucleic acid
genomes
C. Viruses were once independent cells that became dependent on host cells
D. None of these choices
B. Hosts gained the ability to replicate semi-autonomously and transmit their nucleic acid
genomes
- Which of the following is not a strength of the primordial genes hypothesis?
A. The existence of RdRps
B. An ancient lineage that infects all three domains of life
C. The existence of reverse transcriptase
D. Present day viruses are intracellular parasites
D. Present day viruses are intracellular parasites
- What is the viral shunt?
A. Increasing the DOM and POM by cell lysis
B. Virus infected cells will sink to the seafloor at a faster rate than uninfected cells
C. Mode of transport for viruses in the ocean
D. Viruses will lyse cells and make nutrients available for bacteria
A. Increasing the DOM and POM by cell lysis
D. Viruses will lyse cells and make nutrients available for bacteria
- Which of the following is not an environmental factor that affects virus dynamics?
A. Pollution
B. Virus morphology
C. Salinity
D. UV radiation
B. Virus morphology
- Which of the following species interactions does not benefit both organisms?
A. Mutualism
B. Synergismc
C. Commensalism
D. Amensalism
C. Commensalism
D. Amensalism
- Which of the following is not a negative interaction?
A. Competition
B. Parasitism
C. Commensalism
D. Antagonism
C. Commensalism
- If a mutualistic organism acquired virulence factors, it would be recognized as a:
A. Mutualist
B. Commensal
C. Parasite
D. Ectosymbiont
C. Parasite
- If one species produces folate that is necessary for another organisms growth, this interaction would be considered as:
A. Predation
B. Parasitism
C. Syntrophism
D. Commensalism
C. Syntrophism
D. Commensalism
- Which of the following is not a mechanism that PGPR utilize to control pathogens?
A. Lytic enzymes
B. Siderophore production
C. Antibiotic production
D. Phytohormone production
D. Phytohormone production
- Once rhizobia enter the plant cell through the infection thread, they undergo rapid multiplication and differentiation into nitrogen-fixing cells called:
A. Elementarybodies
B. Nitromorphs
C. Bacteroids
D. Shizonts
C. Bacteroids
- If you want to find the area in soil that harbors the largest number of bacteria, where should you look?
A. In the surface layer because there is a high concentration of organic material there
B. Immediately adjacent to roots because released root material is rich in amino acids and organic acids that support microbial growth
C. In non-plant associated soil because there is less competition with plants for nutrients
D. In deep soil layers because important microbial nutrients tend to diffuse down through the soil
column
B. Immediately adjacent to roots because released root material is rich in amino acids and organic acids that support microbial growth