How can we help?

You can also find more resources in our Help Center.

48 terms

Microbiology (non majors) Chapter 11

Characterizing and Classifying Prokaryotes
STUDY
PLAY
Name and describe typical prokaryotic morphologies
True or False
All Prokaryotic cells reproduce sexually
FALSE
All Prokaryotic cells reproduce asexually
Three main methods of Prokayotic cell reproduction
Binary fission (most common)
Snapping division
Budding
Describe binary fission
How does budding differ from binary
fission?
In binary fission, the parent cell disappears with the formation of two equal-sized offspring; in contrast, a bud is often much smaller than its parent, and the parent remains to produce more buds.
Describe steps of budding
1. DNA is replicated
2. One daughter DNA molecule is moved into bud
3. Young bud leads to
4. Daughter cell
The arrangement of Prokaryotic cells result from what two aspects of division during binary fission?
Planes in which cells divide
Separation of daughter cells
Produced by Gram-positive Bacillus and Clostridium
Endospores
Defensive strategy against unfavorable conditions
Endospores
What is the basis of Modern Prokaryotic Classification?
genetic relatedness of rRNA sequences
Three domains of Modern Prokaryotic Classification?
Archaea
Bacteria
Eukarya
Give three common features of Archaea
1. Lack true peptidoglycan
2. Cell membrane lipids have branched hydrocarbon chains
3. AUG codon codes for methionine
Give three methods of reproduction for Archaea
binary fission
budding
fragmentation
True or False
Archaea are known to cause disease
FALSE
Archaea are NOT known to cause disease
(not relevant to the human health)
require temperatures over 80ºC
Hyperthermophiles
Depend on greater than 9% NaCl to maintain integrity of cell walls
Halophiles (salt)
Largest group of archaea
Methanogens
One of primary sources of environmental methane
Methanogens living colons of animals
Convert carbon dioxide, hydrogen gas, and organic acids to methane gas
Methanogens
Extremophiles & Methanogens belong to which domain?
Archaea
believed to be similar to earliest bacteria Autotrophic
Deeply branching bacteria
contain photosynthetic lamellae which allows them to absorb light for anabolism
Phototrophic bacteria
Rod-shaped, obligate anaerobes
Important in medicine (toxins) and industry (forms endospores)
Clostridia
Facultative or obligate anaerobes
Lack cell walls
Associated with pneumonia and urinary tract infections
Mycoplasmas
many common in soil
Bacillus
contaminates milk and meat products
Listeria
grows in the body but rarely causes disease
Lactobacillus
cause numerous diseases
Streptococcus and Enterococcus
one of the most common inhabitants of humans
Staphylococcus
Pleomorphic (different shaped) aerobes and facultative anaerobes. Produces metachromatic granules which store phosphate
Examle C. diphtheriae
Corynebacterium
Aerobic rods that sometimes form filaments. Slow growth partly due to mycolic acid in its cell walls
Example M. tuberculosis and M. Leprae
Mycobacterium
Form branching filaments resembling fungi. Important genera include Actinomyces, Nocardia, Streptomyces
Actinomycetes
thrive in environments with low nutrients
Pathogenic: gonorrhea, meningitis, PID, whooping cough
Betaproteobacteria
Some reduce sulfer
Others infect other gram- bacteria
Deltaproteobacteria
Cause blood poisoning and ulcers
Epsilonproteobacteria
Cause fetal blindness, pneumonia and STDs
Chlamydias
Cause syphilis and Lyme disease
Spirochetes
Can cause abdominal, pelvic and blood infections
Bacteroids
The type of reproduction in prokaryotes that results in a palisade arrangement of cells is called
a. pleomorphic division.
b. endospore formation.
c. snapping division.
d. binary fission.
c. snapping division.
The thick-walled reproductive spores produced in the middle of cyanobacterial filaments are called
a. akinetes.
b. terminal endospores.
c. metachromatic granules.
d. heterocysts.
a. akinetes.
Which of the following terms best describes stiff, spiral-shaped prokaryotic cells?
a. cocci
b. bacilli
c. spirilla
d. spirochetes
c. spirilla
Endospores
a. can remain alive for decades.
b. can remain alive in boiling water.
c. live in a state of suspended animation.
d. all of the above
d. all of the above
Halobacterium salinarium is distinctive because
a. it is absolutely dependent on high salt concentrations to maintain its cell wall.
b. it is found in terrestrial volcanic habitats.
c. it photosynthesizes without chlorophyll.
d. it can survive 5 million rad of radiation.
a. it is absolutely dependent on high salt concentrations to
maintain its cell wall.
Photosynthetic bacteria that also fix nitrogen are
a. mycoplasmas.
b. spirilla.
c. bacteroids.
d. cyanobacteria.
a. mycoplasmas.
Which genus is the most common anaerobic human pathogen?
a. Bacteroides
b. Spirochetes
c. Chlamydia
d. Methanopyrus
a. Bacteroides
Flexible spiral-shaped prokaryotes are
a. spirilla.
b. spirochetes.
c. vibrios.
d. rickettsias.
b. spirochetes.
Bacteria that convert nitrogen gas into ammonia are
a. nitrifying bacteria.
b. nitrogenous.
c. nitrogen fixers.
d. nitrification bacteria.
c. nitrogen fixers.
The presence of mycolic acid in the cell wall characterizes
a. Corynebacterium.
b. Listeria.
c. Nocardia.
d. Mycobacterium.
d. Mycobacterium.