Plant StructureAquaponics
Plant Body• Shoot system = leaves
+ stem• Root system• Meristem = cells that
divide for life of plant, can give rise to all plant structures
3 BASIC Organs– Roots– Stems– Leaves
2 BASIC Systems• BOTH SYSTEMS DEPEND ON
THE OTHER– Root System (roots) receive sugars
and other nutrients from photosynthetic parts
– Shoot System (leaves and stems) depends on water & minerals absorbed from the soil by roots.
The plant body cells tissues organs
• A tissue = group of cells with a common structure and function
• An organ = several types of tissues that work together to carry out particular functions
Tissue Types in Vascular Plants• Dermal Tissue
– Covers/ protects plant– Makes cuticle on stems/ leaves– Allows for better H2O absorption
(root hairs)– Make guard cells
• Vascular Tissue (xylem & phloem)– Transport and support– Throughout the plant– Called “veins” in leaves– Called the “stele” in stem or root
• Ground Tissue– Between dermal and vascular tissues– Storage– Photosynthesis (makes sugars)– Support
Dermaltissue
Vasculartissue
Groundtissue
MONOCOT PLANTS vs. DICOT PLANTS
Plant Body- ROOTSRoot Functions
Anchors plant in soil Takes up water and minerals from soil
& gymnosperms
Eudicot and Monocot Roots
Mono = 1 (1 BIG circle)
Eudicot and Monocot Roots• Epidermis-outer layer of
root that protects the underlying tissues of the root.
• Cortex-the inner side of the epidermis. Allows diffusion of water, mineral salts, and oxygen from the root hairs. Stores foods, especially starch.
• Endoderims-Active mineral uptake
Modified Roots• Some plants have modified
roots • Adventitious roots arise
aboveground spread over large areas
• Storage roots hold “food” called root tubers
Plant Body-STEMStem: series of nodes and internodes
FunctionsSupport for the plant body Holds leaves up to light
Transports nutrients throughout plant
Xylem conducts waterand minerals
Phloem transports sugar
Connect roots and leaves and support plant
Eudicot and Monocot Stems
Tissue Organization of Stems• Most Eudicots– vascular tissue consists of vascular bundles that are
arranged in a ring• Most Monocot stems– the vascular bundles are scattered throughout the
ground tissue, rather than forming a ringPith: in young stems, the pith stores food. The pith disappears in older stems.
Cambium: during growing season, cambium produces new phloem to the outside and new xylem to the inside.
Division of Meristem Cells Causes Plant Growth
• Apical Meristem– tips of root and
shoot– increase in height
• Lateral Meristem– cylinders within
plant body– increase in width
• Apical meristems are located at the tips of roots and in the buds of shoots– elongate shoots and roots, a process called primary
growth• Lateral meristems
– add thickness ONLY to woody plants, a process called secondary growth
– 2 lateral meristems: the vascular cambium and the cork cambium• vascular cambium adds layers of vascular tissue
called secondary xylem (wood) and secondary phloem• cork cambium replaces the epidermis with
periderm, which is thicker and tougher (bark)
Types of Meristems (like embryonic stem cells)
Woody Stem GrowthThe stem has three areas: •Bark•Wood•pith
CORK-protects the outer part of the bar
SPRING WOOD (early wood): the part of an annual ring of wood, characterized by large, thin-walled cells, formed during the first part of the growing season.
SUMMER WOOD (late wood): the part of an annual ring of wood, characterized by compact, thick-walled cells, formed during the later part of the growing season.
LE 35-18b
0.5 mm
Vascular cambiumSecondary phloem
Secondaryxylem
Transverse sectionof a three-year-old Tilia (linden)stem (LM)
Late woodEarly wood
0.5 mm
Cork cambium
Cork
Periderm
Xylem rayBark
HOW OLD IS THIS TREE?
Plant Body-LEAF REVIEW
Functions Exposes surface to sunlight
Major site of photosynthesisConserves waterProvides for gas exchange
Blade
Petiole
Leaf = blade + petiole
Stoma = opening in the leaf for
gas exchange, water evaporation
Monocots & Eudicots Leaves• Monocots lack petioles – Base of leaf forms a sheath that envelops stem– Have parallel veins (run length of the blade)
• Eudicot (dicot) have petioles & leaves have a multibranched network of major veins.– Petiole • Only Eudicots NOT Monocots
petiole
Flowering Plant Reproduction
• Flowers are modified leaves, specialized for reproduction (where pollination takes place).
• Flower parts undergo meiosis to produce haploid products– pollen grain– ovule (contains egg cell)
Pollengrains
Ovule
Flower
Meiosis
Mitosis
Mitosis
Development of Fruit and SeedsFrom Flower Parts
TriploidEndosperm
Cell
Ovary
Integument
DiploidZygote
Endosperm
FreshFruit
SeedCoat
Embryo(new plant)
Seed = embryo + stored food + seed coatFruit = ovary wall, mechanism for seed dispersal
Provides nutrition
Flowers, Fruits, and vegetablesA fruit is the part of the plant that develops from a flower. It's also the section of the plant that contains the seeds. (Protects the seeds).
The other parts of plants are considered vegetables. These include the stems, leaves and roots — and even the flower bud.
Dead Center sits the tomato. Why?Botanically speaking, a tomato is a fruit because it is a seed-bearing structure that develops from the ovary of a flowering plant.
In the culinary world sweet = fruits and savory = vegetables: this includes botanical fruits as eggplants, bell peppers, and tomatoes.
Angiosperm Classification and Morphology
– Monocots: grasses, lilies, orchids, corn, palms, onions– Dicots (aka-Eudicots): broadleaf trees, shrubs, most flowers, and
vegetables.
Exit Slip-March 12, 2014
• Draw a picture of a monocot and dicot cross section of a ROOT.
• Draw a picture of a monocot and dicot cross section of a STEM.