How do we classify and group
plants?
• What are the major divisions?
• How are they grouped and classified?
• How do you use a plant identification key?
Plant Taxonomy
• Nonvascular Plants- have
small reduced leaves, no
vascular tissue( veins) no true
roots, and reproduce by spores
or flagellated cells that travel
through water.
Vascular Plants- have true roots,
stems, and leaves with vascular
tissue. Xylem- water and
minerals. Phloem- transports
carbohydrates
Plant Divisions
• nonvascular
Bryophyta- mosses
• vascular
seedless
Lycophyta-club moss
Pterophyta-Ferns
seed plants
Gymnosperms-naked seeds
Angiosperms-flowering plants
Gymnosperm
Coniferophyta- needle or
scale leaf, cones ( conifer)
Anthophyta or Angiosperm
Monocots- parallel veins,
petals in 3’s
Dicots- net veins, petals in
4’s or 5’s
Bryotphytes
Mosses
Moses
• Non-vascular Plants- No tissues
to carry water
• Spores used for reproduction
• No true roots, stem
• Reduced leaves
Liverworts
sporophyte
Mosses
gametophyte
sporophyte
gametophyte
In mosses the dominant stage of
their life cycle they only have
half of their total chromosme
number.
Spore Producing
• Spores are reproductive stages that have
only half the chromosomes or genetic
material.
VASCULAR PLANTS
Lycopodium,
Lycophyta
Pterophyta
Ferns- reproduce with spores but
have veins to carry water
Gymnosperms
Naked seeds or seeds produced in
cones.
Angiosperms or Anthophyta
• Flowering plants
• Seeds produced within a fleshy
fruit with gametes borne within
a flower.
Antheridium
Archegonium
Liliacea
Taxonomy key\identification key
• You always have two choices in a
description of the organisms characteristic
• Choose the correct choice and it takes you
to a name or a number.
dicot
monocot
Opposite Leaf arrangement
Alternate leaf arrangement
Botany
•Tissues, Organs,
and Systems
Vascular Tissue
Xylem (wood)
make up
xylem. They are nonliving tubes
with openings at the ends to carry
water .
trachieds and vessel elements
Transport in Vascular Plants
• Water and minerals begin
movement by osmosis.
through root and root hair
Transport in Plants cont.
capillary action in xylem
vessel element
Adhesion-water vessel wall
Cohesion- water to water
Transpiration- water moves out
through stoma in the leaf.
closed
H2O
Loss of Turgor
Turgor
• Phloem carries carbohydrates
sieve tube elements-connected by sieve plates
Summer Wood
Vascular phloem
Cork cambium
cambium
CORK
Spring
wood
Phloem rays
Heart wood
Vascular Tissue
• Xylem- wood, carries water
Spring wood- larger openings smaller
ring
Summer wood – more compact rigs
are wider
Phloem- carries sugar
phloem rays carry back and forth
Growth Tissue
• Vascular Cambium- grows new xylem to
the inside and phloem to the outside
• Cork cambium- grows new cork to the
outside
BARK- is vascular cambium, phloem, cork
cambium , and cork
11 xylem
4&5
Cortex ( storage, support)
(7,8)
phloem
Merristematic Regions
• Apical Bud
• Root Tips
Apical Meristem
Leaf Primordia
Axillary Bud
Roots
TAP
secondary
DIFFUSE
primary
Germination
• Seeds begin to grow as a result of
cell division using much oxygen
seeds need warm temperatures,
water, and oxygen to germinate but
the seed supplies the food.
hypocotyl
Embryonic Tissue
Seed leaves of
an embryo
Above the
cotyledon
Below the
cotyledon
Embryonic root
maturation
merristematic
Elongation
cap
Leaves- the main photosynthetic
parts of a plant
• Types of
Simple
Compound
Pinnate
Palmate
Leaf Cross Section
• Epidermis- prevents water loss
protects from UV light
• Palisades- photosynthesis zone (
contains much chlorophyll)
• Mesophyll ( spongy layer)- storage of
gases, water and sugar
• Veins – contain xylem and phloem
• Abscision layer- cuts base of
leaf off during defoliation
Stomate
• Stomate- leaf opening for gas
exchange and water loss
• Guard Cells- control opening
of stomate
• Stoma - opening
Photosynthesis
CO2+H2O
light
CnH2n0n+O2
Light- measured as an absorption spectrum,
the wavelengths that are most important
are different for different types of autotrophs
Photosyntheis
•
•
•
•
Plant takes in carbon dioxide\
Plant takes up water
Plant produces sugars
Plant gives off oxygen
Margin (serrate)
petiole
Pinnate
veins
Simple Leaf with Entire Margin and
Pinnate Veins
Angiosperms or Anthophyta
• Flowering plants
• Seeds produced within a fleshy fruit with
gametes borne within a flower.
Perfect Flower
STAMEN- male part of flower
Anther
Filament
PISTIL or CARPEL
stigma
Pollen tube
style
Ovules within the ovary contain an embryo
ovary
2n
3n
Endosperm -food for development 3n
Zygote is 2n
Composite Family
Flower Structures
• Stamen- male floral part
• Anther- produces pollen ( n)
haploid
• Filament- stalk that supports
stamen
Floral Parts
•
•
•
•
Pistil- female floral part
Style- stalk that supports stigma
Stigma- sticky part attracts pollen
Ovary- eggs develop and are
fertilized to become seeds
Plant Response to Light –Photoperiodism
LONG DAY_ require 12 hr. daylight or
more to flower
SHORT DAY-require less than 12 hr
daylight
DAY NEUTRAL – flower according
to maturity not light
Plant Hormones
• Alter cell division
• Increase elongation
• Regulate gene activity
Auxins
Plant Auxin on Agar Block
Auxin Mutants