BIOL111 Lecture 4

• Binomial nomenclature (Genus species)
• Hierarchy (Kingdom, phylum, class, order, family, genus, species)

eukarya and archaea

the common ancestor

nodes are splits where 2 groups separate

a group of groups that includes the nodes of all the individual groups

one group that is the least related to and not included in the clade

2 or more closely related groups that have to be in the same "generation"

shared ancestry, arose from the same origin

similarity in function due to common environment

includes the ancestor and all of the descendants 

 include a common ancestor but not necessarily all of the descendants

contains a descendant that doesn't belong because the common ancestor has not been traced back far enough

trait shared by the group but not found in their ancestor

derived trait shared by group used as evidence of common ancestry

• 1. lose cell wall
• 2. unfold membrane and increase surface area
• 3. form cytoskeleton
• 4. form vacuoles by pinching of membrane
• 5. DNA and ribosomes already attached to membrane; more infolding until they're surrounded into the nucleus and ER
• 6. microtubules from cytoskeleton form flagellum
• 7. form mitochondriaa through endosymbiosis with proteobacterium
• 8. "optional" form chloroplasts through endosymbiosis with cyanobacterium

• "internal and living together"
• one cell "swallows" a prokaryote but end up living together instead of being digested
• after living together for a long time, the genome of the endosymbiont becomes very reduced and may move to the nuclear genome

• double cell membrane around mitochondria
• genes in mitochondria that match bacterial genes
• mitochondria and chloroplasts reproduce by binary fission independent of cell

• nothing specific, it's a term used out of convenience, not a real taxonomic group
• they are eukaryotes that are not plants, fungi, or animals

• "single cone" protists
• referring to single flagella (if present)
• synapomorphy of opisthokonts: posterior flagellum (as in animal sperm)
• 2 featured groups (amoebozoans) - amoebas (loboseans) and slime molds

• unicellular, unikonts
• move via pseudopods and cytoplasmic streaming
• may have "test" or hard shell
• eat via phagocytosis
• some pathogenic (amoebic dysentery - 3rd leading cause of death from parasites)

• unikonts
• most closely related to amoebas
• move by cytoplasmic streamins
• eat via phagocytosis
• form large aggregates
• reproduce via "fruiting bodies" and spores

• protists that typically have long thin pseudopods as compared to amoebas
• 2 featured groups - foraminiferans and radiolarians

• rhizaria that are primarily marine
• secrete CaCO₃ test - formed major limestone deposits in ocean
• pseudopods stick out of test - capture prey, locomotion in some

• rhizaria that have thin, stiff pseudopods stick out of test - assist in floating, increase surface area
• SiO₂ tests - very ornate and unique, used as fossil markers
• marine zooplankton

• protists once grouped together because some lack mitochondria
• 2 featured groups - diplomonads and parabasalids (metamonads)

• unicellular excavates
• no mitochondria, anaerobic
• originally thought "primitive"
• now known to have been lost (evolutionary reversal - had mitochondrial DNA in nucleus)
• flagellated
• symbionts (mutualistic and parasitic)
• examples: giardia (causes "beaver fever"), trichomonas (causes STD in humans) mutualistic symbiont in gut of termites digesting wood

• protists
• common ancestor was where single endosymbiosis event of a cyanobacterium occurred
• glaucophytes - contain small amount of peptidoglycan on inside and outside of chloroplast membrane, same as cyanobacteria
• 2 featured groups - red and green algae

• also called chlorophytes
• photoautotrophic plantae
• diverse morphology - unicellular, colonial, multicellular filaments, multicellular sheets
• freshwater, marine, terrestrial

• plantae
• multicellular, marine (most tropical)
• photoautotrophs
• accessory pigment - color, ability to use different light wavelengths
• souce of agar
• some secrete CaCO₃ - "coralline algae"

• protists
• usually have cellulose in their cell walls
• alveolates have sacs (aveoli) just below their plasma membrane
• stramenophiles, most have 2 flagella, one with hairs

• chromalveolates
• obligate animal parasites
• unicellular
• complex life cycles involving multiple hosts
• non-functional chloroplasts
• cause of malaria (#1 infectious disease, affects red blood cells, transmitted by mosquitoes)

• chromalveolates
• some cause "red tide"
• release neurotoxins
• "paralytic shellfish poisoning"
• vertebrates most affected due to bioaccumulation

• chromalveolates
• photoautotrophs
• multicelluar, large
• marine, temperate, coastal
• grow very quickly
• form kelp forests - extremely important habitat for may animals
• produce alginic acid - anchor to rocks
• gas bladders at base of blades provide buoyancy

• chromalveolates
• very important part of the phytoplankton
• unicellular
• photoautotroph
• cell walls of SiO₂
• widely used in paleolimnology
• source of "diatomacous earth"
• toothpaste, metal polishes, pool filters