BIOL 1202 exam 2

• monera
• protista
• plantae
• fungi
• animalia

• Domain
• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species

• bacteria
• archaea
• eukarya

• bacterial
• archaean
• protistan
• plantae
• fungi
• animalia

• prokaryotic
• eukaryotic

naming and classifying organisms

naming and classifying organisms according to their evolutionary relationships

reconstructing the evolutionary relationhsips among organisms

hypothesized genealogy traced back to the last common ancestor (i.e., the most recent) through hierarchical, dichotomous branching

the principles that guide the production of phylogenetic trees, a.k.a., cladograms

point where things intersect like on the graph where they branch off

• an entire branch
• the entire graph/branch

• a monophyletic group
• an ancestral species and all of its descendants

the common ancestor of species in the group

construct hypothesized phylogenetic trees

morphological data for extinct species

can provide superficially similar traits that lack homology with one another

share common ancestry

lack of similarity among taxa

do not share common ancestry

similarity among taxa

more closely they are related

group whose relationships we are trying to resolve

• a species known to have an older most recent common ancestor with the ingroup than the ingroup's most recent common ancestor
• helps identify shared ancestral and shared derived characters (unique to a clade)

one that requires the fewest evolutionary events

• innate defenses, acquired immunity
• external barriers
• 2 nonspecific internal defenses

• skin
• mucous membranes
• stomach

• physical barrier to microbia entry
• inhospitable environment for growth
• dry, dead cells at surface
• sweat/sebaceous glands secreting acids and natural antibiotics like lactic acid

• mucous membraes of respiratory and digestive tracts well-defined
• secretions have antibacterial enzymes

if microbes swallowed, acids and protein-digesting enzymes destroy them

continental drift

continental drift

.2-1.0 micrometers in diameter

10-100 micrometers

• viruses
• viroids
• prions
• they are not organisms because they don't have all of the characteristics of living organisms

• .05-.2 micrometers
• come in may different shapes

• genome
• capsid
• sometimes, an envelope

• genetic information
• can be either single-stranded or double stranded DNA or RNA

protein coat which surrounds and protects the genome

membrane (phospholipid bilayer) which surrounds the capsid

• to take control of a host cell to produe more virus particles
• a biological hijacking
• cell type that a virus will infect is usually very specific and the host species which the virus can infect are often a narrow range

they are not alive

• even simpler and smaller than viruses
• small fragments of single-stranded RNA (either linear or circular) with no protein coat

• take over the cell it infects
• plant pathogens which can infect citrus, potatoes, and other crop species

• unusual infectious particles
• NO GENETIC MATERIAL
• improperly folded version of a natural protein
• this wrongly folded protein causes other copies to convert from the correct folding pattern into the incorect
• as the bad copies accumulate, they result in physical changes in the tissue

• linked to degenerative diseases of nervous tissue, especially the brain
• most recently, "mad cow disease"
• Creutzfeldt-Jakob disease and kuru

not certain, but probably developed as a by-product of living organisms

• survive 3000x more radiation than humans
• tolerate extreme dehydration, heat, and cold
• used to "chew up" toxic waste
• "super bacterium"

Bacteria and Archaea

semi-rigid, permeable, made of peptidoglycan (carbohydrate with amino acids attached). Gives bacteria the different types of characteristic shapes

• bacilli: rod-shaped
• cocci: spherical
• spirilla: helical or corkscrew shaped

• either capsules or slime layers composed of polysaccarides and/or proteins
• function is to attach the bacteria to a surface and act as a protective layer

highly organized, firmly attached to cell wall

less organized, loosely attached to cell wall

hair-like structures on the surface of certain bacteria which aid in attachment

• about half the bacterial species are capable of motion using this
• filaments which extend from the membrane of a cell and are used for cellular locomotion
• structurally different from eukaryotic flagella

• protective "resting" structures
• bacteria surrounded by durable cell wall
• resistant to extreme conditions: extreme dehydration, extreme hot or cold, most poisons
• will persist until conditions are favorable then will develop into bacteria

• asexual in the form of binary fission (the entire bacterial chromosome is replicated and passed on to each daughter cell)
• sexual in the form of conjugation using plasmids (some bacteria are able to transfer genetic information between cells by bacterial conjugation: the transfer of genetic information [a plasmid] between two bacteria via a special sex pili. this plasmid is a small double-stranded ring of DNA that carries extrachromosomal genes in some bacteria)

• autotrophs, using photosynthesis (sunlight) or chemosynthesis (inorganic chemicals)
• heterotrophs, including symbiotes: may occur aerobically or anaerobically, some cases food is obtained through a mutualistic symbiotic relationship in exchange for some other commodity

• gonorrhea
• syphilis
• TB
• Lyme disease

• some pathogenic bacteria have developed this because of the widespread use (and misuse) of antibiotics
• 70% of bacterial infections contracted in hospitals are resisted to at least 1 antibiotic

• similar: single-celled, prokaryotes, small size
• different: cell membrane lipids structure, cell wall composition, rRNA subunit sequences,

• kingdom which represents an unusual mix of organisms
• all eukaryotic, mostly unicellular
• differences between the protists and the rest of the eukaryotes not quite as clear

• fungus-like protists: unicellular decomposers
• plant-like protists: (phytoplankton and algae) represent base of most aquatic food webs (lots of photosynthesis and O₂ production

• water molds
• slime molds

• have a two part life cycle in which the cells of many "individuals" form an interactive aggregate which is almost multicellular (mobile feeding stage and stationary reproductive stage with fruiting bodies that produce spores)
• acellular slime molds - division myxomycota
• cellular slime molds - division acrasiomycota

(division oomycota): characterized by filamentous bodies and mobile flagellated (can swim) gametes

• multi-nucleated acellular organisms
• are acellular (without cells) because mobile stage goes through mitosis but not cytokinesis (splitting of cells)
• moves through decaying material engulfing bateria and food particles

• single celled feeding stage
• characterized by individual solitary cells
• amoeboid movement using pseudopodia
• aggregate (clump up) for reproduction during environmental stress

• dinoflagellates - division pyrrophyta
• diatoms - division chrysophyta
• euglenoids - division euglenophyta
• simple plants (algae)

most are marine, 2 flagella

freshwater or marine, glasslike shells with holes to allow for exchange of substances

• most freshwater
• 1-3 flagella
• mostly photosynthetic
• lack cell wall
• have photoreceptor called "eyespot"

• some species of plant-like protists (the "seaweeds" have just been moved from Kingdom Plantae to Protista
• 3 divisions:
• red algae - division rhodophyta