LESSON 2 Flashcards
composed of outer covering of the plant
Dermal Tissue system
- Are external skin layer of the plant which extend all over the entire surface of body.
- Consisting single layer flattened cells
Epidermis
These are the flattened cells that can be seen in epidermis
Straight Walled
Wavey Walled
Beaded Walled
Functions of Epidermis
- Protection of internal tissue from mechanical injuries
- Prevention of excessive evaporation of water
- Protects them from excessive radiation of heat from the sun
- It acts as store house of water.
- It has minor function in photosyntheis and secretion
Structures found in Epidermis layer
Stomata
Trichomes
Functions of stomata
they perform gaseous exchange and transpiration
Types of Stomata arrangement
- Diacytic (caryophylaceous)
- Anisocytic (cruciferous)
- Anomocytic (irregular)
5.Paracytic (parallel) - Actinocytic (radiated)
accompanied by 2 subsidiary cells
Diacytic
there is an equal cells accompanied by 3 subsidiary cells.
Anisocytic
stoma is surrounded by varying number of subsidiary cells.
Anomocytic
stoma is surrounded by 2 subsidiary cells the long access of which are parallel to that of the stoma.
Paracytic
the stoma is surrounded by circles of radiating cells.
Actinocytic
2 types of dermal tissue system
Epidermis
Periderm
they are manute openings usually found in epidermis of the leaves, flowers and fruits of the plants.
Stomata
they are elongated out growth of one or more epidermal cells found on the leaves sometimes on the stems for protection.
Trichomes
Functions of trichomes
to prevent the clogging of the stomata due to dust accumulation
Types of Trichomes
Clothing hairs
Glandular trichomes
this is the layer immediate below epidermis it consist of 3 kinds of cells _____, _____, and ______.
Periderm
Phellen cells
Phellogen cells
Phelloderm cells
they are consist of vascular bundles which are distributed in the stele, and the central cylinder of the stem surrounded by the epidermis and each bundle is made up of _______ and ______.
Vascular Tissue System
Xylem and Phloem
made up of xylem, phloem and cambium
stele
represented by the cortex, hypodermis, pith, mesophyll, portion of the midrid of the leaves
Ground Tissue System
ground tissue system is made up of:
Parenchyma
Collenchyma
Scelerenchyma
this is a collection of cells whose main function is for storage of food materials
parenchyma
storage of air inside the parenchyma
aerenchyma
- flexible in nature it gives stencil strength to the growing organs in being extensible
- use to manufacture sugar and starch.
collenchyma
- consist of very long narrow thick lignified cells usually pointed at both ends.
- they give strength, rigidity, flexibility, and elasticity to the plant body enabling them to withstand various strains.
sclerenchyma
cell content found in plants:
starch
protein
cacium oxalate crystals
mucilage
they are polysaccharides containing amylopectin and the meta amylose
starch
responsible for viscosity of starch
amylopectin
they are usually found abundantly in the endosperm of most seeds.
protein
they are excretory products of plant metabolism
calcium oxalate crystals
these are the polysaccharides complexes of sugar and uronic acid usually formed from the cell walls of the plants
mucilage
function of xylem and phloem
Xylem transports and stores water and water-soluble nutrients in vascular plants. Phloem is responsible for transporting sugars, proteins, and other organic molecules in plants
