botany final
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- coevolutionary associations
- when plants and animals rely on each other and subsequently change over time based on this relationship
- Angiosperms use animals in 3 ways
- protection, pollination, and fruit/seed dispersal
- outbreeding vs. inbreeding
- out: uniting sperm and egg from genetically different plants of same species; in: self-fertilization
- outbreeding is better than inbreeding because
- genetic diversity
- Plants attract animals for pollination by:
- rewards, scent &/or colors (nectar guides) (bracts)
- abiotic dispersal
- using wind or water
- biotic dispersal
- animals poop seeds out, fruits change colors, dry fruits attach to body of an animal (external dispersal)
- earliest fossils
- stromatolites
- endosymbiosis
- prokaryotic cell ingested by another cell and living there as an organelle
- secondary endosymbiosis
- endosymbiosis of a eukaryotic cell by another eukaryote
- 5 types of protists
- euglenids, dinoflagellates, stramenopiles, red algae, chlorophytes
- euglenids
- autotrophic, contractile vacuole, eyespot, pellicle, chloroplasts from secondary endosymbiosis, chlorophyll a+b, E storage= paramylon
- dinoflagellates
- accessory pigment= peridinin, chloroplasts from secondary endosymbiosis( happened twice), E storage= starch, celluslose plates- 2 perpendicular grooves with flagella, some bioluminescent, algal bloom, red tide
- stramenopiles
- 2 flagella: 1 smooth, 1 "hairy", chloroplasts from secondary endosymbiosis of red alga, chlorophyll a & c and fucoxanthin, E storage= laminarin
- diatoms (stramenopile)
- 2 silica "glass shells", make insecticides and filters
- golden algae (stramenopile)
- often form colonies, can have cellulose or silica
- brown algae (stramenopile)
- multicellular "seaweeds", cellulose embedded in matrix of algin, **biggest protist group**
- red algae
- lack flagella, sister to green plants, primary endosymbiosis, accesory pigment: phycobilins, E storage= Floridean starch, cell walls= cellulose embedded in polysaccharides, ex: agar
- chlorophytes
- green algae, sister to streptophytes, primary endosymbiosis, chlorophyll a&b, E storage= starch, cellulose cell wall
- fungi
- heterotrophic organisms that are sister to animals (not plants)
- dominant generation in fungi
- haploid
- heterotrophic (fungi)
- absorptive mode of nutrition
- fungi are mainly:
- saprophytes (absorb nutrients from dead stuff), also parasites, some symbiotic, some predatory
- fungi cell wall
- chitin
- fungi E storage
- lipids
- fungi body
- mycelium (mass of multicellular filaments- hyphae)
- Do fungi have vascular tissue?
- No!
- what kind of spores on fungi?
- Abundant spores; asexual and sexual; sexual spores used to characterize each group
- symbiotic fungi on/in plant roots
- mycorrhizal fungi
- fungi inside roots
- endomycorrhizae (90% of all plant species)
- fungi on outside of roots
- ectomycorrhizae
- Fungal groups
- Chytrids, Zygomycetes, Ascomycetes, Basidiomycetes, Lichens
- chytrids
- primitive fungi, has zoospores
- zygomycetes
- black bread molds, for zygosporangium-> meiosis-> ascospores
- ascomycetes
- sac fungi, septa in hyphae w/ simple spore, forms ascus-> meiosis-> ascospores
- examples of ascomycetes
-
ergot- hallucinogen, LSD
brewer's yeast - basidiomycetes
- mushrooms, dikaryotic filaments (contain 2 different types of nuclei) with specialized cross walls that control flow of organelles (dolipore septa)
- sexual part of mushroom life cycle
- 2 nuclei-> basidium-> meiosis-> basidiospores
- reproductive structure that bears basidia
- mushroom
- specific area on the mushroom that bear basidia
- gills
- lichens
- symbiotic association between fungus and alga, fungus= house, alga= food-maker
- lichens reproduce by ____ reproduction by ___
- asexual reproduction by propagules
- 3 types of lichens
-
crustose= "crusty"
fruticose= "bushy"
foliose= "leafy" - shared derived charatres of ALL green plants:
-
Chlorophyll a+b
starch
2 anterior flagella - streptophytes characteristics
-
cell division w/ phragmoplast
sperm with 2 subapical flagella
oogamy (large egg fuses w/ small sperm)
complex multicellular body w/ parenchyma tissue and plasmodesmata(cytoplasmic channels between cells) - Charophytes
- coloechaete probably very similar to ancestor of land plants, gametophyte generation is the only persistent generation
- why did more advanced land plants become less dependent on water?
- directly related to water dependence (less dependent on wter you are, the more land area you can colonize)
- Embryophytes
- "land plants"
- Why did embryophytes move onto land?
- water provides bath of nutrients, constantly hydrated and supported BUT has a very limited amount of light and CO2
- Embryophytes adaptations to living on land
-
spores with a sporopollenin wall (resists drying out and decay)
flavonoids (uv protection)
cuticle
archegonia(egg producing) and antheridia (sperm producing)
embryo (protects young plant)
apical meristem - 1st group of living embryophytes
- "bryophytes"
- why is "bryophytes" bot monophyletic?
- because tracheophytes are not included
- sporangium
- general term for spore-producing structure in a plant= capsule in bryophytes
- liverworts 2 types of growth forms:
- thallose and leafy (90% of species)
- thallus
- plant body that lacks true leaves, stems, and roots
- stalked body that grows by cell elongation
- sprophyte
- mosses
- erect lefy dominant gametophyte w/ creeping "stems" and multicellular rhizoids
- mosses gametophyte body possesses:
-
hydroids (water-conducting), and leptoids (food-conducting)
no true xylem or phloem - mosses capsule possesses:
- stomata w/ guard cells
- economic and useful moss:
- sphagmun moss
- mosses incresing adaptations to life on land:
-
stomata= regulated pores for gas exchange and transpiration
polyphenolics= chemical compounds for rigidity ex: lignin - why would u need more support on land?
- gravity force
- tracheophytes characteristics
-
sporophyte dominant generation!
branched plant body developing more specialized apical meristems
true vascular tissue (xylem and phloem)! - why a branched sporophhyte dominant life cycle?
-
allows for production of many spoers
harmful recessive alleles can be masked
genetic variation - Lycophytes
- spike-mosses, club-mosses, and quillworts
- Microphylls
- in Lycophytes; small leaves with one vein
- True Roots
- in lycophytes; multicellular, complex, underground organ for absorbing water and nutrients
- Lateral sporangia
- in lycophytes; on sprophylls, often concentrated in specialized areas= strobilus
- Development of heterospory
- in lycophytes; sprorophyte body that produces two different types of spores (megaspores and microspores) -> unisexual gametophytes
- Euphyllophytes characteristics
-
multiflagellate sperm
endogenous roots
overtopping growth (unequarl branching of apical meristem)
megaphylls = large leves with many veins - seed plants characteristics
-
axillary branching- lateral buds
secondary growth
wood- vascular cambium
heterospory- allowed for evolution of SEED! - ovule
- young seed (with unfertilized egg and integument)
- seed
- mature ovule (w/ fertilized egg)
- gymnosperms
- coniferls, cycads, ginkgo, gnetophytes
- conifers
- cone-bearing plants
- conifer characteristics
-
simple magaphylls (needles or scales)
well-developed wood
cone
microsporangia on strobilus - ex: of conifer
- pacific yew= source of taxal -> used to treat ovarian cancer
- cycads
-
like coontie
palm-like growth
soft wood
coralloid roots (cyanobacteria that fix nitrogen & produce toxins)
seeds in a strobilus
seeds dispersed by vertebrates (also contain cycasin) - ginkgo
-
1 species "living fossil"
deciduous trees
simple leaves with dichotomous venation
trees with long shoots and spur shoots
microsporangia clustered on strobili
medicinal plant for improving memory - gnetophytes
- 3 genera left today, share some characteristics with angiosperms
- angiosperms characteristics
-
simple leaves w/ network of veins
xylem w/ vessel elements
sieve tube elements and companion cells
female gametophyte (embryo sac)
double fertilization
flower
fruit - microsporangia
- pollen sacs
- microspores
- pollen grains
- major angiosperm groups
-
"basal families"
magnoliids
monocots
eudicots