Transcript File - Mrs. Roberts` Science Resource Page

Plant Phyla
But before we get into phyla . . .
To what domain do plants belong?
 EUKARYA!!
 To what kingdom do plants belong?
 Plants (Plantae)
 What are some characteristics that ALL
plants share?
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Cell nuclei (Eukarya)
Cell walls
Multicellular
Photosynthesis
Evidence suggests that green algae is the
ancestor of modern plants. Why?
 Plants live on land and in water.
 Adaptations that allow plants to live on land
include:
 Mechanisms for retaining moisture: cuticle
and stomata (see p. 614)
 Means of transporting resources: vascular
system (see p. 614)
 Able to grow upright: lignin (see p. 614)
 Mechanisms for reproduction: pollen and
seeds (see p. 614)
Classifying plants
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Plants are classified into four main groups:
1.
Mosses and Liverwort (Bryophyta)
2.
Ferns (Pteridophyta)
3.
Conifers (Gymnosperms)
4.
Flowering Plants (Angiosperms)
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All are different in appearance, structure and
behaviour.
Mosses - Bryophyta
Mosses are non-vascular plants -- they
cannot transport fluids through their bodies.
 Instead, they must rely on surrounding
moisture to do this job for them.
 Though small in stature, mosses are very
important members of our ecosystem.
 They lay the foundations for other plant
growth, prevent erosion, and contribute to
the lush green appearance of many forested
areas.
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Mosses - 2
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The 24,000 bryophyte species, sometimes
grouped into a single phylum are now
grouped in three phyla:
1.
Mosses (Bryophyta),
2.
Liverworts (Hepatophyta) and
3.
Hornworts (Anthoceraphyta).
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They reproduce by spores, never have
flowers, and can be found growing on the
ground, on rocks, and on other plants.
Mosses
Liverworts and Hornworts
The Fern - Pteridophyta
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Ferns have a vascular system to transport fluids
through their bodies but like the mosses, they
reproduce from spores rather than seeds.
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The main phylum, the Ferns (Pteridophyta) includes
around 12,000 species.
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Three other phyla are included as fern allies: the
Horsetails, Club Mosses and Whisk Ferns
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Ferns also have a gametophyte and sporophyte
stage, but the gametophyte stage is very short.
Conifers - Gymnosperms
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The gymnosperms reproduce from seeds instead of
spores.
The seeds, however, are "naked" (Greek: gummnos) -not covered by an ovary.
Usually, the seed is produced inside a cone-like
structure such as a pine cone which is why they are
called "conifer."
Some conifers, such as the Yew and Ginko, produce
their seeds inside a berry-like structure.
Conifers are fairly easy to identify: In addition to
cones, these trees and shrubs typically have needle-like,
scale-like or awl-like leaves.
And they NEVER have flowers.
Conifers - 2
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Approximately 600 species are counted as conifers
including the pines, firs, spruces, cedars, junipers,
and yew.
Species within the conifer ranks give us pine nuts -pesto's magic ingredient -- as well as juniper berries
for gin.
Conifer allies include three small phyla containing
fewer than 200 species all together:
Gingko (Ginkophyta)
Cycads (Cycadophyta) ;
And herb-like cone-bearing plants (Gnetophyta)
such as Ephedra.
Conifers
Angiosperms (Flowering Plants):
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Angiosperms have flowers and fruit.
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A flower is the reproductive structure of
flowering plants, and they protect a plant’s
gametes and fertilized eggs (just like woody
cones do for most gymnosperms).
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A fruit is the mature ovary of a flower.
Examples: apples and peaches
Further classification of flowering
plants…
Botanists classify flowering plants into two
groups based on two basic kinds of seeds:
seeds with one or two cotyledons.
 A cotyledon is an embryonic leaf inside a
seed. They are often called “seed leaves.”
 This develops into a seedling, and then
eventually a fully developed plant.
 The two groups based on seeds are monocots
and dicots.
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Monocots
Monocots are flowering plants whose
embryos have one seed leaf.
 They generally have parallel veins in long,
narrow leaves (such as in an iris or lily).
 Their flowers usually occur in multiples of 3,
and bundles of vascular tissue are scattered
throughout the stem.
 Examples: corn, wheat, rice, grasses, irises,
and lillies
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Dicots
Dicots are flowering plants whose embryos
have two seed leaves.
 They have leaves with netlike veins.
 Flowers usually occur in multiples of four or
five, and bundles of vascular tissue are
arranged in rings.
 Examples: deciduous trees, peanuts
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Quick Review
Main types of plants: mosses, ferns,
gymnosperms, and angiosperms
 Mosses: nonvascular; reproduce via spores
 Ferns: vascular; reproduce via spores
 Gymnosperms: nonflowering; reproduce via
“naked seeds” meaning they do not produce
fruit
 Angiosperms: flowering; reproduce via seeds
that are protected in mature ovaries called
fruit
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