Plants

• root system


  all of a plant's roots, which anchor it in the soil, absorb & transport minerals & water, & store food
• Roots are not photosynthetic & rely on carbohydrates being imported from other parts of the plant
• shoot system


  the aerial portion of a plant body, consisting of stems, leaves, & flowers
• root


  an organ in vascular plants that anchors the plant & enables it to absorb water & minerals from the soil
• taproot


  a main vertical root that develops from an embryonic root & gives rise to lateral (branch) roots

  • can store sugar & starches for later use
  • systems usually go deep into the soil & are adapted to where groundwater is far from the surface
• lateral root


  a root that arises from the pericycle of an established root
• adventitious root


  a root that arises from the stem when the embryonic root dies

  • each small root will form its own lateral roots resulting in a fibrous root system
  • usually not very deep
  • helps prevent erosion
• root hair


  a tiny extension of a root epidermal cell, growing just behind the root tip & increasing surface area for absorption of water & minerals

  • constantly replaced
• modified roots

  • can develop from stems, leaves, or other roots
  • used for support, anchorage, storage of water & nutrients, & can help absorb oxygen from the air
• stem


  a vascular plant organ consisting of an alternating system of nodes & internodes that support the leaves & reproductive structures
• node


  a point along the stem of a plant @ which leaves are attached
• internode


  a segment of a plant stem between the points where leaves are attached
• axillary bud


  structure that has the potential to form a lateral shoot, or branch

  • appears in the angle formed between a leaf & the stem
• apical bud


  a bud @ the tip of a plant stem

  • aka terminal bud
  • removing this usually stimulates growth of axillary buds
• leaf


  the main photosynthetic organ of vascular plants
• blade


  the flattened portion of a typical leaf
• petiole


  the stalk of a leaf which joins the leaf to a node of the stem

  • grasses & other monocots lack these
• veins


  a vascular bundle in a leaf
• Label the leaves as monocot or dicot based on the arrangement of their veins.

  A) dicot

  B) monocot

  
• Label the leaves as simple or compound.

  A) simple

  B) compound

  
• Some leaves have adaptations that allow them to have additional functions including

  • support
  • protection
  • storage
  • reproduction
• tissue system


  one or more tissues organized into a functional unit connecting the organs of a plant; continuous throughout the plant
• dermal tissue system


  outer protective covering of plants; forms the 1st line of defense against physical damage & pathogens
• epidermis


  dermal tissue of non-woody plants, usually consisting of a single layer of tightly packed cells
• cuticle


  waxy covering on the surface of stems & leaves that acts as an adaptation that prevents desiccation (water loss) in terrestrial plants
• periderm


  protective coat that replaces the epidermis in woody plants during secondary growth, formed from the cork & cork cambium
• vascular tissue system


  a transport system formed by xylem & phloem throughout a vascular plant
• xylem


  vascular plant tissue consisting of tubular dead cells that conduct most of the water & minerals upwards from the roots to the rest of the plant
• phloem


  vascular plant tissue consisting of living cells arranged into elongated tubes that transport sugar & other organic nutrients throughout the plant
• stele


  vascular tissue of a root or stem
• The arrangement of the stele varies depending on the species & the organ
• vascular cylinder


  in angiosperms, the stele in the root
• vascular bundle


  in angiosperms, the stele in the stem & leaves
• ground tissue system


  plant tissues that are neither vascular or dermal, fulfilling a variety of functions, such as storage, photosynthesis, & support
• pith


  ground tissue that's internal to the vascular tissue in a stem
• cortex


  ground tissue that's between the vascular tissue & the dermal tissue in a root or dicot stem
• parenchyma cells


  a relatively unspecialized plant cell type that carries out most of the metabolism, synthesizes & stores organic products, & develops into a more differentiated cell type

  • have walls that are thin & flexible
  • large central vacuole
  • photosynthesis occurs here
• collenchyma cells


  a flexible plant cell type that occurs in strands of cylinders that support young parts of the plant w/o restraining growth

  • have thicker primary walls
  • when mature, these cells are alive & flexible, elongating w/ the stems & leaves
• sclerenchyma cells


  a rigid, supportive plant cell type possessing thick secondary walls strengthened by lignin @ maturity

  • cannot elongate, found in parts that have stopped growing
  • many are dead @ maturity
  • two types: sclereids & fibers
• tracheid


  a long, tapered water-conducting cell found in the xylem of nearly all vascular plants