Plant Organs Flashcards
Features of monocots and dicots
Monocots- 1 seed leaf, fibrous roots, parallel veins, scattered v.b, x3
Dicots- 2 seed leaves, tap roots, rigid, net veins, x4/5
Function of roots
Anchor the plants
Absorb water and minerals
Storage
What is the function of the root cap ?
Protects tissues from damage
Secretes mucilaginous lubricant- movement and growth med. bacteria.
Perception of gravity- amyloplasts act as gravity sensors.
Meristematic region
Cells mostly cuboidal with large vacuoles and centrally located nucleus.
1)protoderm 2) ground meristem 3)procambium.
What happens in zone of elongation
Cells become several times original length and width. Small vacuoles merge together to create a vacuole occupying 90% of cell
Root hair zone
Cells deferenciate into various distinctive cell types.
Epidermal cells develop root hairs which increase s/a
Casparian strip
Casparian strip is where the endodermal cells meet.
Endodermis is the inner boundary of
Cortex.
Cells of the cortex store food.
Function of the casparian strip
Prevents water passing through the cell walls
Regulates entry and exit to the plant
Excludes harmful materials and retain useful ones.
What is the pericycle
It’s a layer of parenchyma cells lying directly inside the endodermis. Gives rise to part of the vascular cambium and cork cambium.
Produces cork tissue(periderm) impregnated with Suberin for waterproofing and protection
Give examples of specialised roots
Food storage roots Water storage roots Propagative roots Pneumatophores Buttress roots Parasitic roots
What is the function of the shoot system
Photosynthesis
Reproduction and dispersal
Food and water conduction
Give examples of specialised stems
Rhizomes
Runners and shoots
Tubers
Bulbs
Explain the term phyllotaxy
Arrangement of leaves on the stem
Describe leaf shapes
Pinnately - leaflets in pairs along petiole
Biponnatley- leaflets subdivided
Palmately - all leaflets attached at same point
