Chapter 21- Virused And Bacteria Flashcards
The reproduction of microorganisms is self-limiting because the accumulation of waste products can be _____, the supply of nutrients may _____, and other organisms may _____.
Toxic, run out, prey on them.
What are the four modes of nutrition in prokaryotic cells?
Photoautotrophs, chemoautotrophs, photoheterotrophs, and chemoheterotrophs.
Give a brief description of photoautotrophs.
Synthesize their own organic compounds, using sunlight as the energy source and carbon dioxide as the carbon source.
Give a brief description of chemoautotrophs.
Utilize carbon dioxide and produce organic compounds, using the energy in simple inorganic substances.
Give a brief description of photoheterotrophs.
Use sunlight as an energy source but their carbon must come from organic compounds—not CO2.
Give a brief description of chemoautotrophs.
Include parasitic types that draw nutrition from living hosts and saprobic types that obtain nutrition from products, wastes, or remains of other organisms.
Define pathogen and give examples.
Infectious, disease causing agents.
Examples: bacteria, virus, protozoans.
What sorts of things could be used as an energy source for bacteria?
Hydrogen sulfide, nitrites, sunlight, and ammonia.
What modes can bacteria use to obtain nutrition?
Photosynthesis and chemosynthesis.
What are spherical bacterium called?
Cocci.
What are rod shaped bacterium called?
Bacillus.
What is peptidoglycan? How is it used? Where is it found?
Composed of polysaccharides cross linked with proteins. Found in the cell wall.
What allows bacteria to join together to transfer genes?
Pili.
List common characteristics of bacteria.
Some may have hairlike pili. Some may have rigid cell walls. Some may have flagella and move about. Some may have a polysaccharide covering. Photosynthesis. Heterotrophy. Chemosynthesis. They posses circular DNA molecules. Single chromosome.
Where is DNA found in bacteria?
As a single circular thread, and possibly as additional pieces.
One of the newest techniques to identify bacteria is to determine their _____.
Nucleotide sequences.
Traditionally, how have bacteria been grouped?
Mode of nutrition.
Response to staining techniques.
Energy source.
Pathogenicity or nonpathogenicity.
What is swamp gas? What bacterium is most likely found in the swamp?
Methane. Methanogens.
Which type of bacterium is restricted to the waste piles of coal mines?
Extreme thermophiles.
What makes archaebacteria different from other monerans?
Absence of peptidoglycan.
The methane producing bacteria (methanogens) belong to what group?
Archaebacteria.
Describe archaebacteria.
Present, anaerobic, chemosynthesis, halophilic, and heterotrophic.
Heterocysts are regions in filaments cyanobacteria that can break and allow for reproduction by _____.
Fragmentation.
ALL autotrophic bacteria synthesizes what?
ATP.
When nutrients are scarce, some bacteria form _____.
Endospores.
Describe endospores.
Resistant bodies.
Enable some bacteria to survive for long periods of time.
May contain concentrated poisons.
The strongest poison known to humans is produced by ____.
Clostridium botulinum.
Describe the location and role of the bacterium E. coil.
Normal inhabitant of the human intestinal tract.
Produces conditions that prevent invasion by other bacteria.
Enhances digestion, particularly the digestion of fats.
Produces vitamin K.
May cause high infant mortality by producing severe diarrhea.
Borrelia burgdorferi is the cause of what disease?
Lyme disease.
What are able to make responses to chemicals, light, gravity, and oxygen concentration?
Bacteria.
In many aspects, bacteria are more “advanced” in their _____ than in their _____.
Behavior, structure.
What are small circular molecules of DNA in bacteria called?
Plasmids.
What is the process by which one bacterial cell transfers DNA to another called?
Conjugation.
Why do most scientists not consider viruses to be alive?
Their metabolic machinery is borrowed from the host cell.
What is smallpox caused by?
Virus.
What is polio caused by?
Virus.
What is influenza caused by?
Virus.
What is syphilis caused by?
Bacteria.
What is herpes caused by?
Virus.
List some characteristics of a virus.
Nucleic acid core.
Noncellular organization.
Protein coat.
They include some forms that are able to attack bacteria.
What are plant viruses primarily transmitted by?
Animals.
When a virus takes over the machinery of a cell, it forces the cell to manufacture more ______.
Viral particles.
The lysogenic pathway is characterized by passive replication of viral ____.
DNA.
What are retroviruses characterized by?
An RNA core.
Temperature pathways of replication.
The enzyme reverse transcriptase.
Being the causative agent for AIDS.
Lengthy periods of latency are most often associated with viruses that ______.
Infect animal cells.
Viroids differ from viruses in that the former lack a ____.
Protein coat.
Describe halophils.
“Salt lovers”
Describe cyanobacteria.
Can form heterocysts, valuable in nitrogen fixation.
Describe thermophiles.
Bacteria that live in temperatures that are usually not usually conducive to life.
Describe actinomycetes.
Can serve as a a source of antibiotics.
Describe methanogens.
Produce “swamp gas.”
Viruses are not able to move themselves or reproduce by themselves. Some biologists consider them life where others do not. ALL viruses contain instructions to manufacture themselves.
Viruses are not able to move themselves or reproduce by themselves. Some biologists consider them life where others do not. ALL viruses contain instructions to manufacture themselves.
List in order of smallest to largest.
Viruses Plants Bacteria Protistans Fungi
Viruses Bacteria Protistans Fungi Plants
