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Botany Exam 2 - Coggle Diagram

- - - - Derived novel trait
    - - Apomorphy shared by two or more taxa
      - Hypothesized to have evolved in their most recent common ancestor
      - Synonymous with homology
    - - Character newer than
    - - Character older than
    - - Trait has gained or lost independently in separate lineages during evolution
      - Convergent evolution leads to species independently sharing a trait that is different from the trait inferred to have been present in their common ancestor
    - - Independent evolution of a similar trait in two or more taxa
  - - - Filamentous
      - Apical bud
  - - - Only divide at tip
      - Cytokinesis in a single plane
    - - Cytokinesis in oblique planes
  - - - Large complex plants
      - Specialized organ systems
    - - Unique mutant
    - - Cooksonia eg
  - - - Side axial
      - On leaf
  - - - Isotomous
    - - anisotomous
  - - - Produce new organs
      - Produce new tissue
      - From shoot apex
  - - - Bryophyte gametophyte
      - Fern (monilophyte) gametophyte
      - Vascular plant sporophyte
    - - Lycophytes (multicellular)
      - Monilophytes (single cell)
      - Spermatophytes (multicellular)
  - - - Ground meristem
      - Procambium
      - Protoderm
- - - - One of the earliest features of land plants
      - All but liverworts with examples
      - Similar Shapes
        
        Early Devonian sporangia ~400 mya stomata scattered across sporangia
      - Extinct lineages
        
        Rhyniophytes, Cooksonia
      - Similarities link to similar functions in extant angiosperms
        
        Some evidence of air chambers
        
        Bean-like shape
        
        Inner wall thickening
      - Aid in desiccating sporophyte
        
        Likely the origin of stomata
        
        Aid in desiccation of sporophyte
        
        Stomata near sporophyte sporangia
        
        Aid in spore dispersal
        
        Likely not regulated
        
        May have permitted some CO2 to enter
        
        No intercellular space
      - Lower stomatal frequency
        
        Support early role different from today
        
        Location on non-photosynthetic sporophyte tissue in early lineages
        
        Extant early lineages have stomata that only open
      - Intercellular spaces
        
        Pseudostomata continuous with epidermis or hypodermis, no space
        
        Space filled with fluid with space made by cells pulling apart
        
        Stomatal canal, small air space
        
        Aid in diffusion of minerals and nutrients from gametophyte to sporophyte
        
        Cell death
      - Floeren Plants
        
        Monocot (grasses)
        
        Dumbbell shape
        
        Same direction as epidermal cells
        
        Eudicot
        
        Kidney-shaped
        
        Random orientation
  - - - Active metabolic processes
        
        Increase turgor pressure
        
        Moves ions, water follows by osmosis
        
        Hypotonic to hypertonic
      - Cytoskeleton microfibrils radially oriented
    - - Provides ATP for potassium pump
      - Protons are pumped out
      - Potassium are moved in
      - Ancestral condition filled with chloroplasts
        
        Independent of blue light
      - Closure at night or under water stress
    - - Amount of water loss to carbon gain
      - Close pore during water stress
        
        Reduce transpiration
        
        Maintain hydration
      - Derived character
      - Reduce probability of cavitation
      - ABA responsive in seed plants
        
        Angiosperms additionally respond to VPD
- - - - Only at tips are found organisms that require oxygen in high concentrations
      - Early thermophiles gave way to color environments
        
        Photosynthesis limited by temperature and is unknown above 74 degrees celcius
    - - Important to understanding the origin of photosynthesis
      - Layers of photosynthetic bacteria/cyanobacteria
      - Secrete mucilage sticking together in thin mats on rock surface
      - Create bands of sediment and dead bacteria, growing similar to reef
    - - Cyanobacteria likely the oldest known fossilized organism
      - Close to LUCA ~ 3.5-3.8 bya
      - Fossils very similar to present day species cell structure
      - Chemical clues, 2-methylhopane almost exclusive in cyanobacteria cell walls
    - - Iron formations disappeared
      - Iron-rich oceans were gone
      - Iron loving microbes dropped out of fossil record
      - Oxgen enriched oceans precipitated iron
    - - Photosynthesis reverse respiration; two stages:
        
        Thylakoid reaction
        
        Light reactions
        
        Stromal reactions
        
        Dark reactions
        
        Calvin-Benson-Bassham Cycle
      - Likely evolved in small bits
        
        thylakoid reactions involve dozens of pigments, specialized electron-handling complexes
      - Likely started as sunscreen
      - Early atmosphere without oxygen, so without the protective ozone layer
      - Cyanobacteria with scytonemin in sheath, pigment that protects them for UV radiation
      - Chlorophyll similar to hemoglobin and likely common ancestor
      - Pigments
        
        Molecules that absorb particular wavelengths of light energy and reflect others
        
        Plants appear to be which color?
        
        This is to do ___ of green light?
        
        Reflection
        
        Absorption
        
        Transmission
      - Absorbed light energy
        
        Causes electrons to become excited
        
        Electron bumps to the next orbital
        
        Fate of electron
        
        Passed to electron acceptor
        
        Fall back down to original orbital
        
        Releasing energy
        
        Heat
        
        Fluorescence
      - Absorbance spectrum
        
        Amount of energy absorbed depends on the pigment
        
        Electromagnetic spectrum holds much energy that cannot be used
        
        Visible spectrum used
      - Chlorophyll
        
        Chlorophyll a
        
        most abundant pigment in plants
        
        peak absorbance
        
        430 nm
        
        660 nm
        
        Chlorophyll b
        
        Second most abundant pigment
        
        Peak absorbance
        
        450 nm
        
        650 nm
      - Action spectrum
        
        Indicates that Chlorophyll a & b are not the only pigments
        
        Must have accessory pigments
      - Accessory pigments
        
        Carotenoids
        
        Beta carotene
        
        Help broaden absorption spectrum
        
        Also act as sunscreen
        
        Visible during the fall
      - Resonance energy
        
        Energy absorption and excitation occurs in organized complexes of pigments and proteins called photosystems
        
        Absorbed energy is moved around via resonance energy
        
        Funneled to reaction center
        
        Special chlorophyll a
  - - - Antennal complex
      - accessory
      - Chlorophyll pigments
      - Reaction center
    - - P680
      - Absorb shorter wavelengths
      - Chlorophyll b >> Chlorophyll a
    - - P700
      - Absorb longer wavelengths
      - Chlorophyll a >> Chlorophyll b
    - - Energy of excited electrons released in a stepwise controlled manner
      - May have evolved initially as a way to dissipate excess energy
      - Some of the energy used to make stable, energy-rich molecules that can be used by living cells
    - - Electron passed from PSII to PSI
        
        Excited PSii electron grabbed by pheophytin
        
        Passed to plastoquinone
        
        Passed to cytochrome b6f complex
        
        passed to plastocyanin
        
        Passed to PSI
      - Electron transport from PSI to NADP+
    - - Electron transport chain
      - Joins PSII to PSI
      - All in order to run ATP synthase
  - - - Flow of electrons does not directly creat ATP
      - Electron flow coupled with a flow of protons
      - Electron energy drops when flow through cytochrome complex
        
        Drag protons across membrane
      - Electrons return to chlorophyll
      - Protons trapped in special internal chamber, thylakoids
      - PSI
      - Plastoquinone
      - Cytochrome b6f
      - Plastoquinone
    - - e- from PSII to NADPH
      - NADP+
        
        Is a great oxidizer
        
        Final electron acceptor
      - Helps to build proton motive force
    - - More powerful energy courier than ATP
      - Sulfur bacteria beginnings
        
        One photosystem
        
        Pull electrons off hydrogen sulfide
        
        Chlorophyll = bacteriochlorophyll
        
        H2S
        
        Structure similar to H2O
        
        Sulfur lower redox potential than oxygen
    - - Uses light energy to split water
      - Oxygen evolving complex of PSII
      - Oxygen and protons released
      - Oxygen diffuses out of stomata
      - Protons left behind
    - - Plastoquinone & cytochrome b6f
      - Both work in concert to bring protons from stoma to lumen
      - Builds up the lake of protons
      - Involved in both cyclic and noncyclic photophosphorylation
    - - Use the proton motive force
      - Run the molecular machine
      - Force P1 onto ADP to form ATP
    - - Light provides the energy to drive the thyroid reactions
      - Water provides electrons via photolysis
      - Oxygen is the by-product
      - NADPH is the final electron acceptor
      - Produces some ATP
  - - - Ribulose 1, 5-bisphosphate carboxylase oxygenase
      - Fixes CO2 into organic carbon
      - Calvin-Benson-Bassham pathway
      - Found in most autotrophs
    - - CO2 bound to RuBP (C5)
      - Immediately breaks into 2C3
    - - Energy from ATP stored into C3 molecule
      - Energetic electrons reduce C3
      - Ends in a pool of G3P (C3)
    - - Carbon Shuffling
      - Get the RuBP back (C5)
      - Takes more ATP
    - - RuBisCo binds 2 molecules
        
        CO2 & O2
      - At low CO2, binds to O2
      - Disadvantages
        
        Not as efficient
        
        Produces toxic by-product
      - Sometimes advantages
        
        High light tolerance
        
        reduce photo-inhibition
      - Provides metabolites for other processes, including stress protection proteins
      - Alpine environments
      - Drought prone environments
      - High salinity environments
    - - Production of glucose
      - Building from smaller molecules
      - Occurs in:
        
        Chloroplasts
        
        Amyloplasts
        
        Cytosol
    - - Products of the thylakoid reaction become reactants for the stroll reaction
      - Energy (ATP) from the thylakoid reactions fun the stromal reactions
      - CO2 is fixed into G3P
- - - - Stebbins 1974
      - Vegetative
      - Survival
      - Sexual Union
      - Dispersal
    - - Relatively more CO2
        
        Present atmospheric level oxygen
        
        ~20.9%
        
        ~535x more O2 than CO2
      - during appearance of land plants
        
        8-15x higher in CO2
        
        ~4% O2
        
        Kept tissues thin as internal environment quickly anoxic
        
        Very weak ozone
      - Terrestrialization
        
        ~470Ma
        
        Major evolutionary changes in morphology & reproduction
        
        Multicellular sporophyte
        
        Retain the zygote & embryo within the female gametophyte
        
        Apical cells with 3 cutting faces allow for 3-dimensional parenchymatous tissue
      - Evolved from algae
        
        Charophycean green algae
        
        Streptophyta
        
        Group includes Embryophyta and charophytes
        
        Sometimes grow as flat disc very similar to present day liverworts
      - Fossil Evidence
        
        Earliest evidence from spores and tissue fragments
        
        Mid-Ordovician 470 Ma
        
        Sporopollenin wall
        
        Trilete mark
        
        Cryptospores
        
        Likely liverwort
      - Liverwort macrofossils
        
        ~390 Ma
        
        Middle Devonian
        
        Dichotomously branched
      - First macrofossils
        
        Cooksonia sporophytes
        
        Mid-Late Silurian
        
        ~425 Ma
        
        Gametophytes complex
        
        Stomata
        
        Conducting elements
        
        Similar to extant liverworts
      - Vascular plants
        
        Specialized conducting cells
        
        Evidence from spores ~443 Ma
        
        Tracheid fossils ~415 Ma
        
        Diversity exploded in Devonian (415-360Ma)
        
        Dominant sporophyte no longer restricted to damper areas
    - - Key Inovations
      - Sporophyte generation
        
        Alternation of generations
        
        Gametophyte dominant in early land plants
        
        Sporophyte evolves dominance
      - Vascular tissue
        
        Water conducting cells
        
        Food conducting cells
      - Leaves & Stomata
        
        All land plant sporophytes but liverworts
        
        Ordovician, many seen by Silurian
        
        Often aerial surfaces covered with cuticle
      - Roots
        
        Downward growing rhizomes
        
        Positive gravitropism
        
        Negative phototropism
        
        Evolved a root cap
        
        Evolved a new way to branch
        
        Early roots branched at tip
        
        Some lineages may have evolved from leaves
      - Seed Evolution
        
        Gametophyte
        
        Completely dependent on sporophyte
        
        Egg protected by special layers of tissue
        
        Seed ferns (all extinct)
        
        Naked seed
        
        Angiosperm
        
        Hidden seed
      - Flower Evolution
        
        Stem Specialization
        
        Attraction
        
        Dispersal
        
        Coevolution
      - Summary
        
        Many morphological changes as plants adapted to life on land
        
        Further selection from competition
        
        Diversification accommodate life cycle changes and coevolution
  - - - haplontic (Greek, haploos + einai = single being)
    - - Aka interpolation theory
    - - Current land plants
      - haplodiplontic (Greek, haploos + diploos + einai = single double being)
    - - Heteromorphic generations
      - Sporophyte
        
        Short-lived
        
        Simple
      - Gametophyte
        
        Relatively complex
        
        Persistent
    - - Marchantiophyta
        
        Marchantia liverwort example
        
        Dominant leafy gametophyte
        
        Temporary diploid sporophyte
      - Gametophyte
        
        Dominant life stage
        
        Antheridiophore
        
        Male
        
        Antheridia
        
        Cotains Sperm
        
        Archegoniophore
        
        Female
        
        Archegonia
        
        Contain eggs
        
        Dominant life stage
        
        Antheridial head
        
        Male
        
        Antheridia
        
        Contain sperm
        
        Archegonial head
        
        Female
        
        Archegonia
        
        Contain eggs
      - Sporophyte #
        
        Small, temporary structure
        
        Parasitic on gametophyte
        
        Meiosis occurs within sporangium
        
        Sporocytes (2n)
        
        Spores (1n)
        
        Small, temporary structure
        
        Parasitic on gametophyte
        
        Meiosis occurs within sporangium
        
        Sporocytes (2n)
        
        Spores (1n)
      - Bryophyta
        
        Mnium moss example
        
        Dominant leafy gametophyte
        
        Temporary diploid sporophyte
  - - - Selaginella example
      - Heterosporous
      - Retained within spore walls
      - Sperm must still swim to egg
    - - Both male and female develop within spore wall
      - Small
      - Microgametophytes
        
        Male
        
        Antheridium
        
        Sperm
      - Megagametophytes
        
        Femal
        
        Archegonium
        
        Egg
    - - Heterosporous
      - Reduction in megasporocytes to 1 per megasporangium
      - Micro = male
      - Mega = female
      - Sori
        
        Sporangia
        
        Indusia
      - Large persistent diploid
    - - Polypod fern example
      - Independent gametophyte
      - Independent sporophyte
  - - - Pine example
      - Microgametophyte no longer restricted to water
      - Megagametophyte protected by integuments
      - Microgametophyte
        
        Pollen
      - Megagametophyte
        
        Becomes nutritive tissue
        
        Protected by integuments
        
        Within an ovule
    - - Large dominant diploid stage
      - Gametophyte reduced to microscopic structures
      - The flowering plants are very diverse
      - Annual to perennial
      - Indeterminate growth
    - - Lily example
      - Sporophyte dominant
      - Gametophytes microscopic
    - - Multicellular haploid stage
      - Pollen grain
        
        Immature
        
        Mature germinating
    - - Multicellular haploid individual
      - Egg one of the cells (nuclei)