Plant Parts

1
Plant Parts

• Flowers, Roots, Stems and Leaves

2
Flowers
3
Flower Parts

• Petal - Petals are used to attract insects into
  the flower, they may have guidelines on them and
  be scented.
• Stigma - Is covered in a sticky substance that
  the pollen grains will adhere to.
• Style - The style raises the stigma away from
  the Ovary to decrease the likelihood of pollen
  contamination. It varies in length.
• Ovary - This protects the ovule and once
  fertilization has taken place it will become the
  fruit.
• Ovule - The Ovule is like the egg in animals and
  once fertilization has taken place will become
  the seed.

4
Flower Parts

• Receptacle - This is the flower's attachment to
  the stalk and in some cases becomes part of the
  fruit after fertilization e.g. strawberry.
• Flower stalk - Gives support to the flower and
  elevates the flower for the insects.
• Nectary - This is where a sugary solution
  called nectar is held to attract insects.
• Sepal - Sepals protect the flower whilst the
  flower is developing from a bud. Filament This is
  the stalk of the Anther

5
Flower Parts

• Anther - The Anthers contain pollen sacs. The
  sacs release pollen on to the outside of the
  anthers that brush against insects on entering
  the flowers. The pollen once deposited on the
  insect is transferred to the stigma of another
  flower or the same flower. The ovule is then able
  to be fertilized.
• Filament the stalk that supports the anther
• Stamen the filament and anther
• Pedicle the stalk on which a flower is produced

6
Roots
7
Roots

• Epidermis. A single layer of flattened cells at
  the surface. When first formed, epidermal cells
  have extensions the root hairs which greatly
  increase the surface area available for the
  uptake of nutrients from the soil. The photo
  below shows the root hairs in the region of
  differentiation of a germinating radish seed.
• Cortex. A band of parenchyma cells that develops
  beneath the epidermis. It stores food. Its inner
  surface is bounded by a single layer of cells,
  the
• Endodermis.

8
Roots

• Stele
• Pericycle - the outer boundary of the stele.
  Secondary roots branch from it.
• Xylem - arranged in bundles in a spoke like
  fashion
• Phloem - alternates with xylem
• Cambium - In older parts of the root, another
  meristem forms between the xylem and phloem.
  Mitosis in the cambium produces new "secondary
  xylem" to the inside and secondary phloem to the
  outside.

9
Parts of the leaves and stem
10
Parts of the leaves and stem

• Leaf Blade Wide flattened area of leaf for
  concentrating sunlight on photosynthetic cells.
• Petiole Short stem that attaches leaf to main
  stem or branch.
• Veins Vascular bundles within leaf for
  transport.
• Node Growth region of stem where leaves or new
  branches arise.
• Auxiliary bud Baby leaf or stem (next years
  growth).

11
Simple Leaves
12
Compound Leaves
13
Internal Structure of Leaves
14
Internal Structure

• a) Cuticle Waxy layer water proofing upper
  leaves.
• b) Upper epidermis Upper layer of cells. No
  chloroplasts. Protection.
• c) Palisade Mesophyll Tightly packed upper layer
  of chloroplast containing cells.
• d) Spongy Mesophyll Lower layer of chloroplast
  containing cells. Air spaces around them.
• e) Lower Epidermis Lower external layer of cells
  in leaf.

15
Internal Structure

• f) Vascular Bundle Bundle of many vessels (xylem
  and phloem) for transport.
• g) Xylem Living vascular system carrying water
  minerals throughout plant.
• h) Phloem Living vascular system carrying
  dissolved sugars and organic compounds throughout
  plant.
• i) Guard Cells 2 cells surrounding stomata that
  control rate of gas water exchange.
• j) Stomata Opening between guard cells for gas
  water exchange.