BELLRINGER: Is It a Stem, Leaf,
Root, Flower, Fruit or Seed?
Fruit/Vegetable
Beet
Cabbage
Celery Stalk
Corn Kernel
Onion
Sweet Potato
Tomato
Zucchini
Part of Plant
Fruit/Vegetable
Part of Plant
Beet
Root
Cabbage
leaf
Celery Stalk
Technically a petiole of leaf, not a
stem
Corn Kernel
Seed (fruit)
Onion
Leaf
Sweet Potato
Root
Tomato
Fruit
Zucchini
Fruit
Plant Structure
Aquaponics
Plant
Structure
Overview:
Reproductive shoot (flower)
Terminal bud
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 +flower
Root system
Meristem = cells that
divide for the life of a
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
Dermal
tissue
Ground
Vascular
tissue
tissue
Plant Body- ROOTS
Functions:
1. Anchors plant in soil
2. Takes up water and
minerals from soil
3. Store Food
& gymnosperms
Root 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.
Endodermis-Active
mineral uptake
Primary Root
Growth
Cortex
Vascular cylinder
Epidermis
Key
Root hair
Dermal
Zone of
maturation
Ground
Vascular
Zone of
elongation
Apical
meristem
Root cap
100 µm
Zone of cell
division
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 vascular tissue
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 (protection)
•Wood (xylem)
•Pith (food storage)
CORK-protects the outer part of the bark
SPRING WOOD (early wood): part of an
annual ring of wood. Has large, thin-walled
cells, formed during the first part of the
growing season.
SUMMER WOOD (late wood): part of an
annual ring of wood. Has compact, thickwalled cells, formed during the later part of
the growing season.
HOW OLD IS THIS TREE?
Secondary phloem
Vascular cambium
Secondary
xylem
Cork
cambium
Late wood
Early wood
Periderm
Cork
Transverse section
of a three-yearold Tilia (linden)
stem (LM)
Xylem ray
Bark
0.5 mm
0.5 mm
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)
Flower
Mitosis
Meiosis
Mitosis
Pollen
grains
Ovule
What is the difference
between a fruit and a
vegetable?
Flowers, Fruits, and vegetables
A fruit 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.