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Plant Cells and Tissues Ch 23
Plant Tissue: Label and list function (s) :Epidermis, stoma, cuticle,mesophyll, vascular bundle, xylem, phloem, guard cells
Plant Tissues 1. Dermal Tissue (epidermis)
2. Ground Tissue3. Vascular Tissue
1. EpidermisFlattened cells
Outer coveringProtects body
Cuticle; waxy (not on roots)Prevent water loss
Epidermis:DRAW AND LABELGUARD CELLS & STOMATA
Guard Cells Daytime-fill with
water and Stomata open Night, guard cells
_______, and Stomata ______
Epidermis
Stomata-openings Leaves (mostly
bottom)& stems Control water
loss Gas Exchange Controlled by
Guard Cells
Epidermis Root hairs-on root
epidermal cells Enhance water &
mineral absorption
2. Vascular Tissue A) Xylem-Function: H2O &
Mineral transport from root to leaves.
B) Phloem- Function: Sugar &
other organic material transport throughout plant body
3. Ground TissueMost of the plant tissue.
Functions: photosynthesis, storage
Surrounds vascular tissue
Plant GrowthMeristems—Regions of
actively dividing cells.Rootshoot
Plant Growth
Figure 35.11
This year’s growth(one year old)
Last year’s growth(two years old)
Growth of twoyears ago (threeyears old)
One-year-old sidebranch formedfrom axillary budnear shoot apex
Scars left by terminalbud scales of previouswinters
Leaf scar
Leaf scar
Stem
Leaf scar
Bud scale
Axillary buds
Internode
Node
Terminal bud
Primary
Secondary
Wood and bark
How Vascular tissue is Arranged in stems
Dicot stem
Two Classes of Angiosperms (Anthophyta) ( p. 596)Cotyledons: seed leafMonocots—1
65, 000 speciesGrasses, lily, palms
Dicots—2185,000 speciesTomatoe, oak, parsley
Monocots Dicots# of Cotyledons
Leaf Vein Arrangement
How flower parts are arranged
Arrangement of Vascular Tissue
# of Cotyledons
Leaf Vein Arrangement
How flower parts are arranged
Arrangement of Vascular Tissue
Cotyledon
Structure in the embryo of a seed plant that may form a ‘leaf’ after germination and is commonly known as a seed leaf. The number of cotyledons present in an embryo is an important character in the classification of flowering plants (angiosperms).
Monocotyledons (such as grasses, palms, and lilies) have a single cotyledon, whereas dicotyledons (the majority of plant species) have two. In seeds that also contain endosperm (nutritive tissue), the cotyledons are thin, but where they are the primary food-storing tissue, as in peas and beans, they may be quite large. After germination the cotyledons either remain below ground (hypogeal) or, more commonly, spread out above soil level (epigeal) and become the first green leaves. In gymnosperms there may be up to a dozen cotyledons within each seed.
http://www.ucmp.berkeley.edu/glossary/gloss8/monocotdicot.html
Plant Body *Roots
*Shoots (stems, leaves)
Figure 35.2
Reproductive shoot (flower)
Terminal bud
NodeInternode
Terminalbud
Vegetativeshoot
BladePetiole
Stem
Leaf
Taproot
Lateral roots Rootsystem
Shootsystem
Axillarybud
Plant Body
Plant Body--Roots1.First Part to Grow
Positive Gravitropism
Roots: FunctionAnchorAbsorb water, mineralsStore Nutrients
Prop Roots Grow Above
groundHelp Support
Example: corn,mangrove
Aerial RootsFormed in and exposed to airOrchidsIvyRainforest trees
Root Anatomy Root Cap Root Tip Root Hairs
Plant Body-Shoots Above ground parts
1. Stems Supports leaves, flowers, fruit Contain Vascular Tissue
2. Leaves Photosynthesis Thin & Flat (high SA:V) Veins ( Bundles)
Stomata-open & close
Seeds
Fruits vary from hard and woody to soft. They can have one to multiple seeds, and hard or soft seeds. Some seeds are readily eaten (e.g. peas, nuts), while some are not (e.g. cherry pits, apple seeds).
Two peanut seeds in the hard ovary (left);
apple seeds in the fleshy fruit, composed partly of flower petals and sepals (right).
Cacti adaptations Cacti depend on chlorophyll in the outer tissue of their skin
and stems to conduct photosynthesis for the manufacture of food. Spines protect the plant from animals, shade the plant from the sun and also collect moisture. Extensive shallow root systems are usually radial, allowing for the quick acquisition of large quantities of water when it rains. Because they store water in the core of both stems and roots, cacti are well-suited to dry climates and can survive years of drought on the water collected from a single rainfall.
Many other desert trees and shrubs have also adapted by eliminating leaves -- replacing them with thorns, not spines -- or by greatly reducing leaf size to eliminate transpiration. Such plants also usually have smooth, green bark on stems and trunks serving to both produce food and seal in moisture, such as the Paloverde. Some plants produce ephemeral leaves during the brief rainy season to help increase transpiration and photosynthesis. Sometimes these leaves only last for one day.