Chapter 15 Flashcards
What domains are microbes found in?
Bacteria, Archaea, and Eukarya.
How many species of microbes are in your intestines?
400
How many species of microbes live in your mouth?
500
How many species of microbes live on your skin?
200
Can microbes live in all environments?
Yes
Characteristics of microbes in the Domain Bacteria:
Prokaryotic cells, cell membrane and wall, proteins that function as organelles, and nucleic acids that instruct proteins.
What are the classification of microbes in Domain Bacteria?
Coccus, Bacillus, and Spirochetes.
Cocci bacteria are…
Spherical shaped.
Bacilli bacteria are…
Rod-shaped.
Spirilla bacteria are…
Spiral-shaped.
How is bacteria identified?
Gram staining.
How do bacteria survive in so many habitats?
They form capsules.
How do bacteria reproduce?
Through binary fission.
How long does it take for E. coli to generate?
20 minutes
How long does it take E. coli to go from 1 cell to 20 billion?
12 hours
What is conjugation?
When a bacterium transfers a copy of some or all of its DNA to another bacterium.
What is transduction?
A virus that has pieces of bacterial DNA inadvertently picked up from its previous host and infects a bacterium.
What is transformation?
When a bacterium picks up DNA from its surrounds, usually from dead bacteria.
What do chemoorganotrophs feed on?
Organic materials.
What do chemolithotrophs feed on?
Inorganic materials, such as mine tailings.
What do photoautotrophs feed on?
The sun, which they use to produce glucose.
Why can photoautotrophs photosynthesize?
They have chlorophyll.
Example of a photoautotroph similar to life 2.6 BYA that produced oxygen:
Cyanobacteria
What are some beneficial bacteria?
Probiotic and normal flora.
What do probiotics and normal flora do for us?
They prevent and treat UTIs and GI issues, crowd out bad bacteria, and release lactic acid to prevent harmful bacteria from attaching to the walls of the bladder and urinary tract.
What foods do beneficial bacteria make?
Yogurt, cheese, wine, and beer.
What is nitrogen fixation?
When nitrogen is taken from the atmosphere and is converted into compounds.
True or false: Beneficial bacteria don’t do nitrogen fixation.
False