CPA #9 Questions Flashcards
what are the 8 prokaryotic morphologies?
- bacillus - rod
- coccus - round
- coccobacillus - elongated round
- vibiro- curved rod
- spirillum- spiral shaped; stiff
- spirochete- spiral; flexible
- pleomorphic- vary in shape/size
- star
which 2 groups form endospores?
clostridium & bacillus
what is the benefit of forming endospores?
endospores survive in hostile environments and then can resume germination when conditions improve
what is the difference between an endospore and a reproductive spore?
reproductive spores are true spores and each spore contains complete genetic material and can develop into a clone of the original
do prokaryotes reproduce sexually or asexually?
asexually only
what is the most common method of asexual reproduction?
binary fission
define: viviparity
asexual reproduction; results in death of “mother cell” when multiple offspring are released; offspring grow simultaneously inside mother
define: snapping division
asexual reproduction; occurs when a newly formed cell wall creates tension in the center of the cell
define: binary fission
asexual reproduction; immediately results in two identical daughter cells
define: budding
asexual reproduction; results in a smaller “daughter” cell from an outgrowth of the original cell
what key feature do taxonomists use to classify prokaryotes/categorize them into groups of relatedness?
rRNA; aka “fingerprints”
what are 3 key differences between archaea and bacteria?
- archaea lack peptidoglycan
- Archea do not have phospholipids in plasma membrane
- archea have different initial amino acid in polypeptide chain (archea is methionine; bacteria is N-formylmethionine)
define: extremophiles
require extreme conditions of temp, pH, pressure, or salinity to survive
define: thermophiles
require temps above 45C
define: hyperthermophiles
require temps above 80C
define: halophiles
require salty conditions
define: methanogens
obligate anaerobe; convert CO2, H2, and organic acids into methane gas(CH4) (major component of natural gas)
what key effect do methanogens have on the environment?
convert organic waste to methane gas; aka greenhouse gas because it traps atmospheric heat which contributes to global warming
what characteristics have been used in the past to group bacteria?
morphology, Gram stain, biochemical reactions
what characteristics are used now?
rRNA sequences
what are nitrogen fixers?
some bacteria can reduce nitrogen gas to ammonia
why is nitrogen fixation important?
provides nitrogen in a useable form to other organisms
what subclass of bacteria are low G+C?
Clostridia
Bacillus
Listeria
Lactobacillus
Streptococcus
Staphylococcus
what subclass of bacteria are high G+C?
Corynebacterium
Mycobacterium
what is G+C?
the percentage of all guanine-cytosine base pairs in a genome; useful for Gram+ bacteria
low C+G bacteria
Clostridia: botulism, tetanus
Bacillus: anthrax
Listeria: contaminates dairy
Lactobacillus: produce yogurt, buttermilk, pickles
Streptococcus: strept throat
Staphylococcus: skin
high C+G
Corynebacterium:
Mycobacterium:
What diseases are caused by Archaea?
none
