Plant Opsommings

Die plant liggaam

1. Plant structure and growth: overview

Plante

* Photosynthetic( carbon dioxide, water and sunlight) autotrophs(ability to make own food)

* Organs: body structure, contains two or more types of tissues and have a definite form and function

* Tissue: group of cells and intercellular substance that functions together in one or more specialized tasks

Plant tissue sharing some general features

* Primary cell wall developed around Protoplast: cytoplasm , organelles and plasma membrane

* Primary cell wall: cellulose fibers embedded in a matrix of hemicelluloses and branched carbohydrates

* celluloses fibers + carbohydrates makes wall rigid & flexible

* pectin: bind cells together

* secondary cell wall: addition of celluloses inside the primary wall (as plant grows)

* lignin(lignification anchors) in cell walls (some plants): stiffens the celluloses fibers in the walls & protects components in the wall form physical/chemical damage

* Pits: how water and minerals passes from lignified cells to another

* Primary cell wall: thin and porous

* Pasmodesmata linking: in living plants: amino acids, sugars and other

Shoot system

* Stems, leaves, flowers(angiosperm)

* Highly adapted for photosynthesis

* Max position for exposure to light

Root system

* Anchors

* Absorbs water and dissolved minerals from soil

* Stores carbohydrates

Growth

* Primary growth: from the Apical meristem, clumps of self-perpetuating tissue at the tips of their buds, stems and roots

* Primary tissue: primary plant body

* growth in length

* Secondary growth: from lateral meristems, self-perpetuating cylinders of tissue

* Woody body

* Secondary tissue: secondary plant body

* diameter of older roots and stems

2. Three plant tissue systems

Ground tissue | Parenchyma | * Primary growth * Photosynthesis,respiration,...