Plants For Food and Fibre

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Plants For Food and Fibre

• Structure and Adaptations

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• Plants are found in nearly all habitats on Earth
• Each of these habitats has a unique environment
• Plants have special structures and adaptations
  that allow them to live in these various
  conditions

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Roots

• Roots perform several important functions for
  plants
• They absorb water and minerals from the soil
• They support and anchor the plant so that it is
  not blown over by wind or washed away by water
• They store food to help the plant survive during
  times of scarcity

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Roots (cont.)

• Many plants have a single, prominent taproot with
  numerous small roots coming out of it
• These smaller roots are covered in tiny root
  hairs
• The smaller roots and root hairs increase the
  ability to absorb water and nutrients
• Ex. Moss campion with 2m taproots

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Roots (cont.)

• Other plants have fibrous roots a system of
  shallow, similar-sized roots that can quickly
  soak up moisture
• Ex. Duckweed is a common plant found in ponds and
  has tiny roots that grow off the underside of the
  floating leaves

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Root Crops Carrots (okay)
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Root Crops Beets (vomitous)
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Root Crops Turnips (gross)
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Root Crops Radishes (angry hurl)
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Root Crops Parsnips (absolutely disgusting)
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Root Crops Rutabagas (what the?)
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Diffusion and Osmosis

• Diffusion is a tendency of particles in a gas or
  liquid to become evenly distributed by moving
  from areas of greater concentration to areas of
  lesser concentration.
• Ex. When a perfume bottle is opened in a room
  the scent diffuses throughout the room quite
  quickly.

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Diffusion and Osmosis

• Most cells in most organisms are said to be
  differentially permeable this means that they
  only let certain materials pass in and out of the
  cell.
• Osmosis is the diffusion of water through a
  differentially permeable membrane.

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Stems

• One function of the stem is to transport water
  and nutrients between the leaves and the roots.
  Ex. In a tree trunk
• Heartwood dead wood in the middle
• Xylem carries things upward
• Cambium growing part of the trunk
• Phloem carries things down from the leaves
• Bark woody skin that protects the tree

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Leaves

• During the major growing season a pigment
  called chlorophyll makes leaves green
• Plants use their leaves to combine carbon dioxide
  and water to make oxygen and sugar
• The sugar is an energy-storing chemical in the
  plant
• This process is called photosynthesis

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Leaves (cont.)

• Carbon dioxide enters the plants through tiny
  holes called stomata
• Most of the stoma are on the bottom of the leaf,
  which gives the carbon dioxide easy access to the
  spongy layer of the leaf
• The spongy layer is where much of the leafs
  water is stored.

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Leaves (cont.)

• Guard cells surround each stoma and control the
  size of the stoma
• At night when photosynthesis does not occur, the
  plants release carbon dioxide and let oxygen into
  their cells respiration
• When guard cells absorb water, they swell and the
  stoma opens to let water vapour this loss of
  water by evaporation is called transpiration

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• the cuticle is the waxy layer, the vein is on the
  side in profile