Unit 1 Plants Flashcards
Epidermis
In roots: water absorption, root hairs are extensions of epidermal cells and increase SA, active transport of minerals into epidermal cells, provide some protection
In stems: produce waxy cuticle to prevent water evaporation
Cortex
Allows lateral flow of water and dissolved substances from epidermis to vascular cylinder (roots) between vascular bundles (stem). Food storage (starch granules)
Endodermis
Innermost layer of the cortex just prior to the vascular cylinder or stale.
In cylinder it’s one cell thick
Selective barrier that regulates passage of substances from the cortex into vascular tissue of the stele
Wall b/w endodermal cells has waxy material that prevents substances from passing b/w cells forcing them to go through the cells
Pericycle
Outermost layer of vascular cylinder (stele)
Cells may become meristematic and divide to produce branch roots
Vascular cylinder (stele)
Composed of: pericycle, vascular tissues of phloem and xylem in
Monocots: includes unspecialized vascular cells called pith
Dicots: small & have cross shape
Xylem
- Mixed tissue of vessel/ tracheid cells
- transports water and dissolved minerals from roots to leaves
Phloem
- Mixed tissue of sieve tube/ companion cells
- transports sugars/ biochemical a in various directions around the plant
Vascular bundle
vascular cylinder branches into strands that run the length of the stem
Contains xylem and phloem and in
Monocot: fiber cap/ cambium
Dicot: monkey face
Vascular cambium
Lateral meristem in vascular bundle of dicot. Produces new xylem and phloem causing stem to grow in girth
Fiber cap
Made of thick cells (sclerenchyma) that support the vascular bundle. Located just above the phloem of the dicot stem vascular bundle
Stem pith
Storage of food (starch granules). Allows lateral movement of substances b/w vascular bundles.
Pith rays
Thin rays of pith cells b/w the vascular bundles of dicot that connect the pith and cortex
Monocot
Single seed leaf
Dicot
2 seed leaves
