Plant Structure
Aquaponics
Reproductive shoot (flower)
Terminal bud
Plant
Structure
Overview:
Node
Internode
Terminal
bud
Vegetable
shoot
Leaf
Shoot
system
Blade
Petiole
Axillary
bud
Stem
Taproot
Lateral roots
Root
system
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
Division of Meristem
Cells
Causes Plant Growth
Apical Meristem
tips of root and shoot
increase in height (called
primary growth)
Lateral Meristem
cylinders within plant
body
increase in width (called
secondary growth)
Only in woody plants
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
Plant Body- ROOTS
Functions:
1. Anchors plant in soil
2. Takes up water and
minerals from soil
3. Store Food
& gymnosperms
Roots Tissues
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-STEM
Stem: series of nodes and internodes
Functions
Support for the plant body
Holds leaves up to light
Transports nutrients throughout plant
Xylem conducts water
and minerals
Phloem transports
sugar
Connect roots and leaves and support plant
Tissue Organization of Stems
Pith: 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.
Vascular Tissue: Xylem on inside Phloem on the
outside
Two Kinds of Plant Vascular Tissue
• Xylem
•Carries H2O, dissolved
nutrients.
•Generally upward
movement.
•Dead at maturity.
• Phloem
•Carries products of
Photosynthesis.
•Alive at maturity
•Generally downward
movement
Woody Stem Growth
The 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.
What is the function of
leaves?
What makes up a leaf?
Cuticle
Epidermis
Mesophyll Layer
Vascular System
Stomata
Leaf Structure-Dermal layers
Cuticle-The thin waxy
covering on the outer
surface.
prevents water loss
within the leaf. (Plants
that live entirely within
water do not have a
cuticle).
Directly underneath the
cuticle is a layer of cells
called
the epidermis (upper
and lower) protect inner
layers
Leaf Tissues
Mesophyll
Tissue between upper and lower
epidermis
Two types:
Palisade parenchyma (mesophyll) cells
Lots of chloroplasts in these cells
Most photosynthesis occurs here
Spongy parenchyma (mesophyll) cells
Lots of air spaces where O2 and CO2 circulate
Near stomata (Think: sponges have lots of air
spaces)
Veins
Xylem and phloem are continuous from roots through stem to
leaves
Stomata and Guard Cells
The underside portion of a leaf has stomata and is the
site of transpiration (water movement) and gas
exchange.
Stomata help regulate the rate of
transpiration
Guard cells
2 cells on either side of stomata
(surrounds stomata)
regulate water loss
What conditions will promote
closing of guard cells?
Hot, dry, windy conditions
Stoma Opening/Closing
http://academic.kellogg.edu/herbrandsonc/bio111/animations/0021.swf
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)
Flowers, Fruits, and vegetables
A 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.