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Plants (Angiosperm Reproduction (Asexual Reproduction (pros (no need for…

- - - - Self-fertilizing: crop plants, every ovule will develop into a seed
        
        can combine own pollen and ovule to form a zygote
        
        doesn't increase genetic diversity
        
        most angiosperms evolved mechanisms to prevent
      - Abiotic: wind
      - Biotic: insects, bees, etc.
  - - - seed = embryo + endosperm (proteins, oils, starch)
      - in eudicot plants: endosperm exported to cotyledon
      - water = 5-15% of seed weight
      - seed enters dormancy as it matures
        
        imbibition (water uptake to seed), then see germinates and develops into mature plant
      - seed coat - protects embryo and food supply
  - - - develops into pollen grain
  - - - in megasporangium of each ovule, megasporocyte undergoes meiosis --> produces 4 megaspores
        
        1 survives, becomes female gametophyte (embryo sac)
        
        4 parts
        
        polar nuclei
        
        synergids
        
        Egg (haploid, n)
        
        antipodal cells
    - - on anther, microsporangium containing microsporocytes that undergo meiosis --> 4 haploid microspores
        
        microspore undergoes mitosis, forms male gametophyte (pollen grain -- haploid, generative cell + tube cell)
        
        generative cell divides to form 2 sperm, pass into tube cell during maturation #
  - - - division of single cell
      - division of entire organsim
      - budding
    - - 2 forms
        
        fragmentation: detached fragment develops into whole new plant
        
        Apomixis - plants produce seeds without pollination or fertilization
    - - no need for pollinator
      - desirable genomes
      - stronger progeny
      - less costly for parent resources
    - - identical genomes (bad if environment changes)
      - not dispersed
      - must grow in current environment
- - - - casused by meristem: plant tissue that remains embryonic
  - - - nonwoody and woody plants
      - tips of roots and shoots and axillary buds of shoots
  - - - vascular cambium and cork cambium
        
        vascular cambium adds layers of vascular tissue (secondary xylem and phloem)
        
        cork cambium replaces epidermis with thicker, tougher periderm
- - - - 2 types
        
        Fibrous root
        
        thin roots spread out below soil surface
        
        many spread out from stem
        
        taproot
        
        lateral roots responsible for absorption
        
        allows plant to grow tall
        
        1 vertical root
      - defintion: organ that anchors a vascular plant in soil, absorbs minerals and water, stores carbohydrates
      - Adventitious - plant organ growing in unusual location
      - Root hairs: thin finger-like extensions of root epidermal cells
    - - definition: organ to which leaves are attatched
        
        to elongate and orient shoot in way that maximizes leaf photosynthesis
      - alternating system
        
        nodes: points at which leaves are attached
        
        internodes: stem segments between nodes
      - 2 buds
        
        apical bud: where most growth appears aka terminal bud
        
        axillary bud: potential to form lateral shoot or branch, at angle
    - - main photosynthetic organ
        
        responsible for
        
        photosynthesis
        
        gas exchange
        
        heat dissipation
        
        defense against pathogens and herbivores
      - 2 parts
        
        blade
        
        contains vascular tissue (for transport)
        
        stalk (petiole): joins leaf to stem at a node
      - Tissue Organization
        
        mesophyll: cells specialized for photosynthesis
        
        stomata: gas exchange
        
        guard cells: open and close stomata
        
        vascular tissue (xylem and phloem): transport nutrients and photosynthetic products
  - - - outer protectivee covering
      - defense against pathogens and physical damage
      - non-woody plants
        
        epidermis: tightly packed cells
        
        cuticle: waxy coating
      - woody plants
        
        periderm: offers more protection
    - - facilitates transport of materials through plant
      - provides mechanical support
      - 2 types of tissues
        
        xylem: conducts water and dissolved minerals from roots into shoots
        
        Phloem: transports sugars to roots
      - Stele: Vascular tissue of a root or stem
        
        Vascular cylinder in root
        
        Vascular bundles in stems and leaves
    - - pith: internal to vascular tissue
      - cortex: external to vascular tissue