Collenchyma & Sclerenchyma Flashcards
Collenchyma consists of?
Living cells
Collenchyma shape
Polygonal-shaped and elongated
How are Collenchyma packed?
Closely packed together
Collenchyma cell walls
Cell walls are unevenly thickened which usually occurs at the corner of the cell wall
Contains pits
What causes thickening in collenchyma
cellulose, pectin and hemicellulose.
Where are Collenchyma present
herbaceous plants
Collenchyma functions
Acts as a mechanical support in herbaceous plant
Allows the cells to expand and be stretched as the young stem grows
Some of cells contain chloroplasts to carry out photosynthesis
Sclerenchyma types
Sclerenchyma fibres and Sclereids (Stone Cells)
Sclerenchyma fibres shape
Elongated, polygonal-shaped with tapering ends
What do mature sclerenchyma tissues consist of
dead cells tightly packed together with no intercellular air spaces
Sclerenchyma secondary cell walls charactersitics
Thick, lignified secondary cell walls impermeable to water, solutes and gases.
Sclerenchyma cell wall chatracteristics
Thin primary cell wall
Thick secondary cell wall
Pits present
What is in the middle of sclerenchyma fibres
empty lumen
Where are sclerenchyma fibres located
Epidermis of stems or roots,
vascular bundles
midribs of leaves.
Sclerenchyma fibres function
Acts as supporting tissue
Tapered ends of the sclerenchyma fibres overlap and interlock
increasing their combine strength
