test 2 bio1102 Flashcards
prokaryotic cells are smaller than _____
eukaryotes
prokaryotes live in … too ____
too cold,
hot,
salty,
acidic,
alkaline for eukaryotes to survive
microscopic parasite
pathogen
most bacteria are benign or malignant.
benign
prokarys decomp ___ ____ sustaining chem cycles
dead organisms
prokarys have three common cell shapes …
cocci
bacili
spiral
cocci
spherical prokary cells
cocci (singular) sometimes occur in chains called …
streptococci
bacilli
rod-shaped prokarys
bacilli may be _____ or filamentous
threadlike
spiral prokarys are like …
corkscrews or worms
nearly all prokaryotes have a ___ ___
cell wall
what do cell walls provide?
- physical protection
- prevent cell from hypotonic env. (bursting)
when prokarys are stained with Gram stain, cell walls are either _____ or ______
gram-positive or gram-negative
gram-positive
thinner and simpler cell walls that ABSORB dye.
containing peptidoglycan
gram-negative
less peptidoglycan, moreee complex and more likely to cause disease. LESS absorption
cell walls of many prokaryotes are covered by a _____
capsule
capsule made of what
sticky layer of polysaccharides or protein
the capsule does what?
-enables prokarys to adhere to substrate or other individuals
-shields pathogenic prokarys from attacks by a host’s immune system
flagella help with what?
-prokarys movement in environment (propel)
fimbrae:
hairlike projections that enable prokarys to stick
prokary population growth:
- occurs by binary fission
- can produce rapidly within hours
- generate plenty genetic variation
binary fission
how prokarys reproduce by copying DNA
