Bio Chapter 36

  1. indeterminate growth in plants
    when plants are able to grow continuously in any direction in response to favorable conditions
  2. herbaceous plant
    • the "generic" plant
    • a seed plant that lacks wood and has a relatively short-lived stem
  3. phenotypic plasticity
    • roots show a great deal of this, meaning that they are plastic/changeable, depending on environmental conditions
    • genetically identical individuals will have very different-looking root systems if they are growing in different environments
  4. Form: rosette
    • compact forms that form in species that have extremely reduced internodes
    • dandelions and cabbages are examples
  5. Modified Shoots: cacti
    • stems are enlarged into water-storage organs
    • its leaves are modified into protective structures called spines
  6. Modified Shoots: Stolons
    • runs over the soil surface, produces roots and leaves at each node
    • Image Upload 1
  7. Modified Shoots: Rhizomes
    • stems that grow horizontally instead of vertically.
    • stolons grow aboveground, while rhizomes spread belowground.
    • store starch
    • Image Upload 2
  8. Modified Shoots: Tubers
    • underground, swollen ends of thizomes that function as carbohydrate-storage organs
    • the eyes of a potato are nodes in the stem where new branches may arise
  9. Modified Shoots: Thorns
    modified stems that help protect the plant from attacks by large herbivores
  10. protoderm
    • gives rise to the dermal tissue system.
    • this is also called the epidermis
  11. ground meristem
    forms the ground tissue system, which makes up the bulk of the plant body and is responsible for photosynthesis and storage
  12. procambium
    forms the vascular tissue system, which provides support and transports water and nutrients between the root system and shoot system.
  13. Zone of cellular division
    • closest behind the root cap
    • contains the apical meristem, where cells are actively dividing
  14. zone of cellular elongation
    • middle position behind the root cap
    • made up of cells that are recently derived from primary meristematic tissues
    • actively increases in length
  15. zone of cellular maturation
    • farthest away root cap
    • where older cells complete their differentiation into dermal, vascular, and ground tissues
  16. pith
    ground tissue inside the vascular bundles
  17. cortex
    ground tissue outside the vascular bundles
  18. cuticle
    • epidermal cells secrete the cuticle, a waxy layer on the outside of the plant
    • the cuticlereduces the amount of water that is lost by evaporation from the interior of the plant.
    • also prevents bacteria and pathogens from entering plant
  19. stomata
    allow gases to get through the cuticle by diffusion
  20. Parenchyma cells
    • are the most abundant and versatile plant cells
    • primary site of photosynthesis
    • also store starch deposits
    • most are totipotent
  21. collenchyma cells
    • function mainly in support
    • even when mature, their cell walls retain the ability to stretch and elongate
    • "strings" of celery include many strands of collenchyma cells
  22. sclerenchyma cells
    • support cells that produce a thick secondary cell wall in addition to the thin primary cell wall found in all cells
    • secondary cell wall contains the rigid compound lignin.
    • support after active growth has ended
    • dead at maturity
  23. sclerenchyma: fibers
    extremely elongated, may be used in manufacture of paper, hemp, or linen
  24. sclerenchyma: sclereids
    • short, have variable shapes
    • function in protection
    • touch coats of seeds and the thick shells of nuts
  25. xylem
    water and dissolved ions from the roots travel up to shoots
  26. phloem
    sugar, amino acids, chemical signals, etc. throughout the whole plant body
  27. tracheids and vessel elements
    • water-conducting cells inside the xylem
    • dead at maturity
    • present in angiosperms
  28. sieve-tube members
    • in phloem, type of parenchyma
    • long, thin cells that have perforated ends called sieve plants
    • responsible for transporting sugar and other nutrients
    • no organelles
  29. companion cells
    • in phloem, type of parenchyma
    • contain all of the organelles normally found in a plant cell
  30. fxn of primary growth
    • to extend the reach of the root and shoot systems
    • increase the plant's ability to absorb light and acquire CO2, H2O, and ions
  31. fxn of secondary growth
    • to increase the amount of conducting tissue available and provide the structural support required for extensive primary growth
    • increases width
    • produces wood
  32. lateral meristem
    • also called a secondary meristem or cambium
    • form cylinders that run the length of a root or stem
    • divide in a way that increases the width of roots and shoots
  33. what does vascular cambium produce?
    • secondary phloem and xylem are only found in gymnosperms and some angiosperms
    • secondary phloem: sugar transport
    • secondary xylem: water transport and structural support, forming wood
    • the parenchyma cells radiate laterally across the xylem and form rays
  34. what does cork cambium produce?
    • corl cells to the outside
    • phelloderm to the inside
    • altogether make up the periderm
    • allows continued protection of the woody stem when it increases in width
    • also protects the shoot system from fire damage
  35. heartwood
    • inner xylem region of a tree
    • provides structural support but no longer transports water
    • darker colored
  36. sapwood
    • outer xylem region of a tree
    • includes active water-conducting xylem tissue
  37. how are growth rings in trees formed?
    • As the growing season ends, conditions dry out or become cooler, so the secondary xylem cells that are produced at this time are smaller, thicker walled, and darker in appearance.
    • this period of no growth is called dormancy
Card Set
Bio Chapter 36
Plant Form and Function