Transcript Plant Classification

Introduction to PLANT CLASSIFICATION
Bellwork
Roots,
leaves, and stems are
very important parts of a
plant. Pick one of those
three parts, and describe in
detail how it helps the plant
survive.
What is Taxonomy?
Taxonomy is the system of
classifying living
organisms. Today, you will
be learning about the
taxonomy of plants
Plants Are in Their Own
Classification Kingdom Because…
?
Click for answer
Plants are multi-cellular eukaryotes—that is, their cells
contain membrane-bound structures called organelles.
Plants differ from other eukaryotes because they have
cell walls that are rigid, composed mainly of cellulose.
The most important characteristic of plants is their
ability to photosynthesize, or make their own food.
Note the tiny green,
spherical structures,
called chloroplasts, near
the edges of the cell walls
in this onion root.
Chloroplasts are essential
to the process of
photosynthesis, in which
captured sunlight is
combined with water and
carbon dioxide in the
presence of the
chlorophyll molecule to
produce oxygen and
sugars that can be used
by animals.
PLANT TAXONOMY
Major Phyla
1. Mosses (Bryophyta)
2. Ferns (Filicinophyta)
3. Conifers (Coniferophyta/Gymnosperms)
4. Angiosperms (Flowering Dicots = 2 seeds parts)
5. Angiosperms (Flowering Monocot s= 1 seed part)
PLANT CLASSIFICATION
 Plant
classification is based on three
main characteristics:



Tissue Structure: vascular or non-vascular.
Seed Structure: naked seeds, covered seeds,
and spores.
Main Body Structures: low to ground, high
from ground, viney, branching, herbs, rigid
trunks, flowering or not, etc.
There are two main classification groups
within the plant taxonomy.
Non-vascular plants lack true roots, stems and leaves. They
absorb water directly from the base on which they grow or from
the air. They must depend on osmosis and diffusion to move
materials in and out of their cell structures. Due to the pull of
gravity, these non-vascular plants do not grow tall because they
have no way of transporting water and food a long distance.
Vascular plants have true roots, stems and leaves. These plants
have well-developed tubes that transport food and water in and
out of their cell structures. Therefore, these plants can grow tall.
What are the names of the tubes that transport water and
glucose throughout the plant?
Xylem tubes carry water and phloem
Click
for answer
tubes
carry
the glucose.
Non-Vascular Bryophytes: mosses, liverworts and
hornworts
Mosses prefer cool, moist, shady
habitats. They grow on soil, rocks,
and the bark of trees, and in bogs
and shallow streams. Moss plants
consist of small, slender stalks
and leaves. They reproduce by
way of spores instead of seeds.
Liverwort
Hornwort
Club Moss
Something Different: Algae
Algae are in the Protist classification. They have both plant and animal
traits.
They are found both as prokaryotes and eukaryotes; some can
photosynthesize; most have cell walls; and some can move about on
their own while others cannot. Algae lack the roots, leaves, and other
structures typical of true plants, so they are non-vascular.
They are the most important
photosynthesizing organism on Earth.
They capture more of the sun’s energy
and produce more oxygen (a byproduct
of photosynthesis) than all plants
combined.
The first green algae appeared more
than 2 billion years ago in the fossil
record—they are believed to be the
most immediate relatives of the green
land plants.
Vascular: trees, bushes, flowering plants, vegetables,
fruits, weeds, ferns
Ferns
Conifers
Flowering Plants
Vegetables
Cells of Vascular Plant Tissue
The first group of vascular plants involves plants known as ferns.
Having true roots, leaves and stems allows ferns to grow tall
because they can easily transport water and food up and down
the plant’s body structure.
Ferns were once the dominant plants on earth and were found in
vast "fern forests". Ferns do not reproduce with seeds as do other
plants, but they reproduce with spores. The spores are located on
the underside of the fern’s leaf, also called a frond.
Spores
The second group of vascular plants are called
gymnosperms, also known as evergreens or conifers. These
plants keep their leaves/needles anywhere from
1-18 years. Examples would be pine trees, spruce, cedar, fir, etc.
The term gymnosperm is derived from two Greek words: gymnos, meaning naked,
and sperma, meaning seed. The seeds of gymnosperms are produced in a cone and
are released from the cone when mature. They are referred to as "naked seeds“
because they are not protected by a covering once they are released from the cone.
The third group of vascular plants are the most complex. They are
the angiosperms. These are the flowering plants that produce
seeds in a fruit. The angiosperms are deciduous, which means they
lose their leaves each fall.
Angiosperms
The Latin term, “angi,”
means enclosed” and
the Greek “sperma,”
means seed.
The term “angiosperm”
means a seed contained
in a vessel, and refers to
flowering plants, in
which seeds mature
within a fruit.
Angiosperm Seeds Come in Two Types:
Monocots & Dicots
A monocot seed has only one part/cotyledon to
it. Monocots are commonly found in plants
that include the iris, lily, corn, orchid, grass
and palm.
Dicots have two
parts/cotyledons to their
seed, or two halves.
Differences Between
Monocots & Dicots
Monocot plants are distinguished
from dicots because they have flower
parts in threes; one cotyledon (seed
leaf); leaf veins that are usually
parallel; vascular tissue in scattered
bundles in the stem; and no true
secondary growth.