Kingdom Plantae
How Plants came to be
Overview of the Plant Kingdom
• Botanists divide the plant kingdom
into four groups based on three
important features:
1. Water conducting tissues
2. Seeds
3. Flowers
Mosses
Ferns
Cone Bearing Plant
Flowering plant
The Plant Life Cycle
• Plants have life cycles that are
characterized by alternation of
generations
• The two generations are the haploid
(N) gametophyte, or gameteproducing plant, and the diploid (2N)
sporophyte, or spore-producing
plant.
Bryophytes
• Type of early plant with no vascular
tissue that draw water in their cells
by osmosis.
Moss
Liverwort
Hornwort
• In just a few million years, plants
grew to a whole new scale on the
landscape.
Q: What caused this increase in size?
A: Vascular Tissue
Vascular tissue
• A type of tissue that is specialized to
conduct water and nutrients through
the body of the plant
Evolution of Vascular Tissue
• Both forms of vascular tissue—xylem
and phloem—can move fluids
throughout the plant body, even
against the force of gravity.
Xylem
• Carry water upwards from the roots
to every part of the plant
Phloem
• Transports nutrients and
carbohydrates produced by
photosynthesis from the leaves
down to the roots
22–3 Seedless Vascular
Plants
Club Mosses
Horsetails
Ferns
Underground Stem
• Over millions of years, plants with
a single trait—the ability to form
seeds—became the most
dominant group of photosynthetic
organisms on land.
• Seed plants are divided into two
groups:
Gymnosperms
• Cone plants
• Bear their seeds directly on the
surfaces of cones
Ex.) conifers, pines, spruces, cycads,
ancient ginkgoes and gnetophytes
Angiosperms
• Flowering plants
• Bear their seeds within a layer of
tissue that protects the seed
Ex.) grasses, flowering trees shrubs,
wild flowers
Monocots and Dicots
• Monocots and dicots are named for
the number of seed leaves, or
cotyledons, in the plant embryo.
Monocots have one seed leaf, and
dicots have two seed leafs
Flowers
• Seed bearing
structures of
angiosperms
Pollen
Entire Male Gamtophyte
Pollen grain
• Contains the male gamete
Pollination
• The transfer of pollen from the male
gametophyte to the female
gametophyte
Seed Coat
• Surrounds and protects the embryo
and keeps the contents of the seed
from drying out
• Can be specialized for dispersal
Flowers and Fruits
• Angiosperms have unique
reproductive organs known as
flowers.
Q: Why are flowers evolutionary
adaptations?
A: they attract animals that pollinate
them
• Flowers contain ovaries, which
surround and protect the seeds
• After pollination, the ovary
develops into a fruit, which
protects the seed and aids in its
dispersal.
Fruit
• Ripened ovary, thick wall of tissue
that surrounds the seed
• Hard, tart fruit protects developing
seed from herbivores
• Ripe, sweet, soft fruit
attracts animals to
Which Plants have better adapted
to live on land?
• Vascular plants also evolved the
ability to produce lignin, a
substance that makes cell walls
rigid.
• The presence of lignin allows
vascular plants to grow upright
and tall
Roots
• Absorb water
and minerals
Leaves
• Collect light for photosynthesis
Veins
• Made of xylem and phloem
Stems
• Used for
support,
connect roots
and leaves,
carry water
between them
Woody and Herbaceous Plants
• Woody plants – Have woody
stems
Ex.) trees, shrubs, vines
Herbaceous Plants
• Plant stems that are smooth and
nonwoody
Ex.) dandelions, petunias, and
sunflowers
Annuals, Biennials, and
Perennials
Annuals
• Angiosperms that complete a life
cycle within one growing season
Biennials
• Angiosperms that complete their life
cycle in two years
• In the first year, biennials germinate
and grow roots, stems, leaves
• During their second year, biennials
grow new stems and leaves and then
produce flowers and seeds
Perennials
• Flowering plants that live for more
than two years