Please enable JavaScript.

Coggle requires JavaScript to display documents.

iGCSE Plant Physiology, GERMINATION, ROOTS, Osmosis is the net diffusion…

- - - - carbon dioxide + water
        CO2 + H2O
        
        light
        =>
        chlorophyll
        
        glucose + oxygen
        C6H12O6 + O2
        
        chains => polysaccharides
        = starch
      - products of the reaction contain
        more energy than oxygen and water
        light energy => chemical energy
      - Limiting factors
        
        ++CO2
        
        ++Temperature
        
        ++Light levels
      - Glucose
        
        Respiration
        
        Needs potassium ions from soil
        For respiration and photosynthesis
        
        disaaccharide sucrose for transport
        
        Starch for storage
        
        polysaccharide cellulose for cell walls
        
        Proteins and DNA
        
        Also needs mineral ions from soil
        
        Nitrates for amino acid production
        Proteins, chlorophyll, dna
        
        Phosphates to make compounds
        Including DNA and cell membranes
        
        Lipids - oils in seeds
        
        Chlorophyll
        
        Also needs magnesium ions from soil
        
        a monosaccharide
      - Two stages
        
        Light dependent
        
        Light absorbed by chlorophyll
        
        Splits water into hydrogen and oxygen
        
        Light + ADP+Phosphate => ATP
        
        Oxygen released as gas
        
        Light independent
        
        Hydrogen from water + ATP + CO2 -> glucose
        
        ATP
        
        From the perspective of biochemistry, ATP is classified as a nucleoside triphosphate, which indicates that it consists of three components: a nitrogenous base (adenine), the sugar ribose, and the triphosphate.
    - - large surface area
        ability to angle to sun
      - many chloroplasts
      - access to water & CO2
      - system of transport
      - gas exchange system
    - - Upper Epidermis (covered by cuticle)
      - Mesophyll
        
        Palisade Cells
        
        Long narrow cells
        
        100s of chloroplasts
        
        Main site of photosynthesis
        
        Spongy Cells
        
        More rounded
        
        Loosely packed
        
        Main gas exchange surface
      - Lower Epidermis (covered by cuticle)
        
        Stomata (holes)
        
        Allows gas exchange
        
        Gap between guard cells
        
        Opens and closes
      - Xylem
        
        Water
        
        Minerals
        
        Transpiration stream
        
        up the plant
      - Phloem
        
        Products of photosynthesis carried
        
        Supplies areas that can't produce food
        
        up and down the plant
  - - - Amino acids
        Proteins
        Chlorophyll
        DNA++
        
        Deficiency -> limited growth
        Older leaves turn yellow
    - - DNA++
        Cell membranes
        
        Deficiency -> poor root growth
        Younger leaves turn purple
    - - Enzymes of respiration
        Photosynthesis
        
        Deficiency -> leave turn yellow
        Width dead spots
    - - Part of chlorophyll molecule
        
        Leaves turn yellow
- - - - animal cell surface membrane
      - plant cell surface membrane
      - plant cell vacuole membrane
    - - Pure water = highest potential
      - Highly concentrated solution = low potential
    - - absorbs water by osmosis
        
        cell swells
        
        cytoplasm pushes against cell wall
        
        turgid (internal pressure)
        
        keeps cells pushed against each other
        
        supports non-woody parts of plant
        
        enabling photosynthesis
    - - loses water by osmosis
        
        cell decreases in volume
        
        flaccid no internal pressure
        
        membrane & cytoplasm
        split away from cell wall
        
        plasmolysed
        
        wilting
  - - - through the stomata
        
        STOMATA
        
        More on the bottom of the leaf
        
        Open and close
        
        Guard cells on either side
        
        banana shape
        
        cell wall near stoma v. thick
        
        In light, swell with water
        via osmosis
        
        contain chloroplasts
        
        in light -> energy used to
        accumulate solutes
        
        1 more item...
        
        turgid -> bend outwards
        
        opening stoma
        
        In dark, flaccid
        
        closing stoma
      - sets up water potential gradient
      - draws up water from xylem
    - - supplies leaves with water
        for photosynthesis
      - carries mineral ions dissolved in water
      - provides water to keep cells turgid
      - allows evaporation to cool the leaves
    - - Light intensity (increases during photosynthesis)
      - Temperature (increases evaporation)
      - Humidity (reduces transpiration)
      - Wind speed (increases evaporation)
  - - - cellulose walls
        imgrenated with lignin
        made by cytoplasm
        
        cells die forming
        hollow tubes lumen
        
        no more cytoplasm
        
        arranged end to end
        
        very strong to hold up plant
        
        impermeable to water
      - become elongated
  - - - also end to end
      - keep cytoplasm & cell walls
      - end of cell has cross-wall of cellulose
        a sieve plate
        
        cytoplasm extends through holes
        
        each cell linked
        
        sieve tube
        
        transport products of photosynthesis
      - NO NUCLEUS
      - controlled by adjacent companion cells
- - - - shoots grow towards
      - most roots ignore, some grow away
    - - shoots grow away
      - roots grow towards
  - - - formed in tip of shoot
      - moves away from the light
        
        unidirectional light -> bending
        (dark side grows more)
      - stimulates growth
- - - - haploid gametes
        in flowers
        
        male in pollen grains
        in anthers of stamens
        
        female ova in ovules
        in ovaries
        
        pollination via stigma
        -> fertilisation
        
        zygote -> seed enclosed in a fruit
        
        pollen grain forms pollen tube
        
        pollen tube grows into the style
        
        pollen grain nucleus moves down tube
        
        Ovule contents -> food store for germination
        
        male nucleus fuses with female nucleus
        
        Ovule wall -> seed coat or testa
        
        Ovary wall -> fruit coat
      - produced by meiosis
      - wind or insect
        
        stamens exposed
        
        stamens enclosed
        
        stigma exposed
        
        stigma enclosed
        
        stigma feathery
        
        stigma sticky
        
        petals large
        
        petals small
        
        petals bright
        
        petals plain/green
        
        nectaries present
        
        nectaries absent
        
        pollen small, smooth, inflated
        
        pollen large, sticky, hooked
  - - - cuttings
      - bulbs = bases of leaves
        swollen with food
        with buds inside
      - runners => ground layers
      - tubers
      - cuttings