Midterm 2 (3.1) Flashcards
Classification of life
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Cocci,
Singular: coccus
Spherical prokaryotes (bacteria)
May occur:
- On their own: cocci
- In pairs: diplococci
- In chains: streptococci
- In clusters: Staphylococci
Bacilli,
Singular: bacillus
Rod shaped prokaryotes (bacteria)
Often solitary
May occur as streptobacilli
Spirilla
Spiral-shaped prokaryotes (bacteria)
- Variety of spiral-like shapes
Endospores
Some bacteria form resistant cells called endospores (ex: Bacillus anthracis) which can withstand harsh conditions
Bacteria
Cell walls composed of peptidoglycan
Peptidoglycan
Sugar polymers cross-linked by short peptides
Archaea
Cell walls made of polysaccharides and protein
Wall may be surrounded by gelatinous capsule
- Protects against host defences
- Protects against dehydration
- Lets them stick together
Phototrophs
Energy from the sun
Chemotrophs
Energy from chemicals
Autotrophs
Get carbon in form of CO2
Heterotroph
Need carbon from organic sources
Heterocysts
Specialized cells that fix nitrogen
Thicker cell walls to prevent oxygen from entering
Decomposers
Break down dead organisms and waste products
Unlock supplies of C, N, other elements
Chemoheterotrophs
Symbiosis
Mutualism
Commensalism
Parasitism