presentation 03 - plant tissues - bio resource site€¦ · plant tissues 1. meristematic tissue :...
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TissuesTissues
an integrated group of cells with a common structure and function
Plant TissuesPlant Tissues
1. Meristematic tissue: rapid cell division, lengthening of shoots and roots
2. Dermal tissue: covering for the plant body
3. Ground tissue: support, photosynthesis, and storage
4. Vascular tissue: conduction of water, food, and dissolved minerals; strengthens and supports the plant
MeristematicMeristematic TissueTissue
� cells that do not differentiate
� cells retain the ability to divide
� Types:� Types:� Apical – primary growth at
root and shoot tips� Lateral – secondary growth
in trees and shrubs � Intercalary – secondary
growth in monocot stems
Apical Apical meristemmeristem
� In shoot tips and root tips
� Allium cepa root tip
Region of cell differentiation/maturation
Region of cell elongation
Root cap
Apical meristem
Region of cell division
Dermal TissuesDermal Tissues� Single layer of cells called the
epidermis in herbaceous plants� Guard cells� Trichomes
Epidermis
� Trichomes� Root hairs
� Functions� Absorption� Secretion of cuticle� Protection� Control of gas exchange
Cuticle
The Ground The Ground Tissue SystemTissue System
Parenchyma cellsParenchyma cells
� spherical-shaped cells
� found throughout plant
� thin primary walls
� living, metabolizing tissue
� functions:� functions:
� Photosynthesis & respiration
� Storage (starch, oil droplets, water, and salts)
� Wound healing & regeneration
CollenchymaCollenchyma
� beneath the epidermis in young stems and in large veins of leaves
� elongated cells that have unevenly thickened cell unevenly thickened cell walls
� alive at maturity� flexible support system� found uniformly throughout
the plant
SclerenchymaSclerenchyma� structural support� two types:
� fibers – support in wood, bark, leaves, stemsstems
� sclereids – protection in fruits, seeds, other plant organs
� primary and secondary cell walls.
� dead at functional maturity
The Vascular The Vascular Tissue SystemTissue System
Complex Complex Vascular TissuesVascular Tissues
� Xylem� Conducts water and dissolved
minerals from the roots
� PhloemConducts dissolved food � Conducts dissolved food materials, carbohydrates, in solution
� Continuous throughout plant
� Support plant body
All 4 types of tissues are present
in the root tip
Young dicot stem Young monocot stem