SPGBIOpoaos

• Plants


  Produce their own food through the process of photosynthesis
• Plants


  Also known as producers/autotrophs
• Simple plant tissues


  • Parenchyma
  • Collenchyma
  • Sclerenchyma
• Parenchyma


  Photosynthesis, Storage, Secretion, Tissue repair
• Sclerenchyma


  Fibers & Sclereids, Support
• Complex plant tissues


  • Epidermis
  • Periderm
  • Xylem
  • Phloem
• Epidermis


  Secretion of cuticle, Protection, Gas exchange
• Periderm


  Secondary growth, replaces epidermis, Protection
• Xylem


  Transports water from the roots, Water conduction, Support
• Phloem


  Conduction, Support, Contains minerals
• Shoot is above the ground
• Root system has the roots
• Roots


  Develop from a portion of the seed embryo called hypocotyl
• Root functions


  • Anchor plant into the soil
  • Absorb water and minerals from the soil
  • Conduct water and dissolved nutrients to and from the shoot
  • Specialized functions in modified root
• Taproot


  Consists of a main primary root, branches out lateral roots, common to dicot plants
• Fibrous root


  Branches out from the bottom part of the stem into several roots, thinner compared to taproot, monocot root
• Root regions (longitudinal section)


  • Root cap
  • Meristematic region
  • Elongation region
  • Maturation region
• Root cap


  Thimble shaped mass of cells that covers and protects the root tip, secretes mucigel to reduce friction
• Meristematic region


  Dome shaped, consists of actively dividing cells
• Elongation region


  Cells undergo enlargement, rectangular/elongated shape, with vacuoles
• Maturation region


  Cells differentiated to form permanent tissues, root hairs aid in water absorption
• Root regions (cross section)


  • Epidermis
  • Cortex
  • Endodermis
  • Stele
• Epidermis


  Outer surface layers, cuticle, lack stomata, protection, water absorption
• Cortex


  Parenchyma cells, storage
• Endodermis


  Innermost layer, Casparian strip
• Stele


  Central cylinder, contains pericycle, vascular tissues, and pith
• Pericycle


  Next to endodermis, actively dividing cells, gives rise to lateral roots
• Vascular tissues


  Xylem and phloem, arrangement varies in monocots and dicots
• Pith


  Core of parenchyma cells
• Dicot roots have a taproot structure, with lateral branches, and the vascular structures are located in the middle
• Monocot roots are fibrous, with vascular bundles arranged in a circular pattern around the central pith
• Stem


  Originates from epicotyl, functions include support, storage, and transportation
• Stem types


  • Herbaceous
  • Woody
• Herbaceous stem


  Soft and green, small diameter, covered with epidermis
• Woody stem


  Tough and not green, grow considerably in height and diameter, covered with cork
• Stem external structures


  • Nodes
  • Internodes
  • Lenticles
  • Leaf scars
  • Buds
  • Bud scales
  • Bud scars
• Nodes


  Areas from which leaves and branches originate
• Internodes


  Areas between 2 nodes
• Lenticles


  Tiny pores for gas exchange
• Leaf scars


  Marks left by fallen leaves