Transcript vascular - The Home Ed Center

What next?
• Now we have a basic understanding of the
basic plant parts, now it is time to learn in
more details the structure and composition
of those parts.
• There are several major characteristics
that are used to classify plants into their
different phyla
How plants are classified
• Non-vascular plants (no seeds)
• Vascular plants without seeds
• Vascular plants with seeds
– Non-flowering
– Flowering
• Monocotyledon (monocot)
• Dicotyledon (dicot)
The 4 Plant Kingdom Phylums
Plant Phyla
Examples
Classification
Characteristics
Bryophyta
Mosses
Non-vascular
Pteridophyta
Ferns
Vascular without seeds
Coniferophyta
Cedars, junipers, pines,
redwoods, yews
Vascular, with seeds, non
flowering
Anthophyta
Flowering plants
Vascular with seeds flowering
Vascular vs. Non-vascular
• Vascular plants are those that have
vascular tissue those that do not have
vascular tissue are non-vascular.
• So what is vascular tissue?
– Vascular tissues are xylem and phloem which
carry water and minerals to the plant.
Vascular Tissue
Responsible for transporting food, water and
other substances around the plant.
There are three main types of Vascular
Tissue:
Phloem
(this one gets the food)
Cambium (this one is between the other two)
Xylem
( this one gets the water)
Non Vascular Plants
• Kingdom Plantae
• Division Bryophyta
– Examples – Mosses
• Characteristics
– Small no more than an inch or so.
– No vascular tissue – no true roots, stems or leaves.
– Transport water into the leaves by diffusion
• Leaves are often single layers of cells so that diffusion can easily be
accomplished.
• Usually have to live near water in shady places
– Mosses are made of 2 parts
• a lower leafy part attached to rhizoids.
–
Anchors the plant and absorbs water and minerals
• The upper part consists of stalks.
– Reproduction
– The gametes (eggs and sperm) are produced in the stalks.
– Eggs are non-motile the sperms are motile. Water is necessary for reproduction so
that the sperm can swim to the non-motile egg.
Non-vascular Plant
Reproduction
Non-vascular Plant
Reproduction
• In mosses the eggs and sperm needed for
sexual reproduction are produced in the top of
the green leafy part of the plant. Water is
necessary for fertilization because the sperm
must swim to the unmoving egg. After
fertilization the zygote remains attached to the
green leafy part and grows into the stalk and
capsule. Thousands of spores are produced in
the capsule. When conditions are right, the
capsule bursts open and the spores are
released.
Seedless Vascular Plants
• Kingdom Plantae
• Division Pteridophyta
– Examples – Ferns
• Characteristics
– Contain xylem and phloem so can grow taller and live in drier areas.
• Still rely on water for the transport of gametes for sexual reproduction
– Fern have 3 parts
• Fronds – the leaves
• Rhizome – and underground stem
• Roots – anchor the plant and transport water and minerals to the plant
– Reproduction
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On the lower surface of the fern fronds are specialized structures that produce spores.
The spores are scattered by the wind.
The spores grow into a small heart shaped type of fern plant.
This small plant produces the eggs and sperm
Water is required to allow the sperm to swim and fertilize the egg.
After fertilization the small plant remains attached to the small plant and will then grow into
the fern that
Seedless Vascular Plant
Reproduction
Seedless Vascular Plant
Reproduction
• On the lower surface of many fronds are specialized
structures that produce spores (which are haploid). Tiny
fern spores are scattered by wind and may eventually fall
on a surface and begin growing. The spores grow into
small hook-shaped plants that are often easily
overlooked. It usually grows no larger than a fingernail.
The small plant produces eggs and sperm and requires
water for the sperm to swim to the eggs. After
fertilization, the zygote which remains attached to the
small plant will grow into the type of fern that most
people recognize.
Seed-bearing Vascular Plants
non-flowering
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Kingdom Plantae
Division Spermothphyta
Sub-Division Gymnosperm
Characteristics
– Contain xylem and phloem
– Seeds are usually contained in cones
• Gymnosperm means “naked seed”
• Seeds are not completely covered
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Do not produce true flowers
Woody plants – only some produce annual rings
Many have needle like leaves
Usually evergreen (stay green all year long)
Have many commercial uses: Paper, housing, flooring, furniture etc.
Reproduction
• Detailed on next slides
Seed-bearing Vascular Plants
non-flowering
Seed-bearing Vascular Plants
non-flowering Reproduction
 First the pine tree must produce two different kinds of
cones. The seed cone and the pollen cone. The seed
cone containing the egg and the pollen cone containing
the pollen grains.
 The spores in the gymnosperm's seed cone become the
female gametophyte and produce the eggs that are
fertilized by large amounts of blown (by the wind) pollen
grains. Which is the spores in the pollen cone known as
the male gametophytes.
Seed-bearing Vascular Plants
non-flowering Reproduction
 When the pollen (sperm) and ovule (egg) join, a diploid zygote
is formed.
 Then the fertilized egg divides through mitosis and grows into
and embryo inside a seed in the seed cone. The embryo
being a young sporophtye.
 Finally the seed will be shed and will soon reach a suitable
environment for it to grow into a new gymnosperm. To make it
possible to grow it uses the stored food inside of the seed.
 The cycle reoccurs when the cones are ready.
Seed-bearing Vascular Plants
Flowering
Kingdom Plantae
•
• Division Spermatophyta
• Sub Division Anthophyta (angiosperm)
• Class
– Class Monocotyledon
– Class Dicotyledon
• Characteristics
– Contain xylem and phloem.
– Seeds are covered by a protective covering called a fruit
• Angiosperm means “covered seed”
– All produce flowers
– Usually deciduous (loose leaves in winter)
– Have many commercial uses: All Fruits and vegetables, honey, baskets,
etc.
– Reproduction
• Will cover this next week
Seed-bearing Vascular Plants
Flowering
• Anthophyta (angiosperms) are divided into
2 classes
– Monocotyledons
– Dicotyledons
• So what are they?
– First we need to know what a cotyledon is.
What is a Cotyledon?
This is the first type of
leaf to grow on a plant.
After the first true leaves
have formed, the
cotyledon leaf withers and
falls off.
Anthophyta (flowering plants):
Monocotyledon
Monocotyledon plants
Mono means one. Has only 1 cotyledon
(Monocot for short)
Starts growing with one leaf.
Flower parts in multiples of 3
Major leaf veins parallel
Stem vasular bundles scattered
Roots are adventitous
Secondary growth absent
Examples: grasses, orchids, lillies,
tulilps, corn, bamboo, and daffodils
Anthophyta (flowering plants):
Dicotyledon
Dicotyledon plants
Di means two. Has 2 cotyledon’s
(Dicot for short)
Starts growing with two leaves.
Flower parts in multiples of 4 or 5
Major leaf veins reticulated (palmate, pinnate, etc.)
Stem vascular bundles in a ring
Roots develop from radicle. Can be any type.
Secondary growth often present
Examples: peaches, pears, carrots, squash etc.
Which is the monocotyledon?
Which is the dicotyledon?
• Monocotyledon
• Dicotyledon
As you will recall one of the major
characteristics that separate plants is the
formation of tissues
Plants have 3 Types of Tissue
Dermal Tissue
Ground Tissue
Vascular Tissue
Plant Tissue
What is tissue?
Cell of the same kind joined together.
Most Plants are Made of 3 Types
of Tissue
Dermal Tissue
Ground Tissue
Vascular Tissue
Dermal Tissue
• This type of tissues is on
the surface of most plants.
• Its purpose is for:
– protection and the
– prevention of water loss.
Ground Tissue
Forms the bulk of the plant’s insides
Photosynthesis
Food storage
Support and Protection
Vascular Tissue
Responsible for moving food,
water and minerals around the
plants. Xylem and Phloem
Vascular Tissue is Made of:
• Xylem
This carries
water up from
the root.
• Phloem
This carries
the food
made in the
leaves to
other parts of
the plant.
•
Cambium
These cells are able to divide
to make more phloem and
xylem tissue. (Dicots only)
Cross section of a monocot
stem
1. A large number of vascular
bundles.
2. The vascular bundles are
scattered in the ground
tissue.
3. No cambium occurs between
the xylem and phloem.
4. There is no distinction
between the cortex and pith.
5. No Secondary thickening.
6. No annual rings are formed.
Cross section of a dicot stem
1. A limited number of vascular
bundles.
2. The vascular bundles are
arranged in a ring.
3. Cambium occurs between
the xylem and phloem.
4. The cortex and pith can be
clearly distinguish.
5. Secondary thickening can
occur.
6. Annual rings are formed due
to secondary thickening.
Monocot vs. Dicot stem
Cross section of a young
dicotyledon stem
• Phloem
• Cambium
• Xylem
• Vascular Bundle
• In young dicotyledon stems, vascular tissue is
usually arranged in groups called Vascular
Bundles.
In dicotyledon stems these bundles are
arranged in a regular pattern as shown above.
• Young Dicotyledon
• Vascular Bundles
• Older Dicotyledon
• Vascular Cylinder
• So…As the young dicotyledon grows
older, the vascular bundles join forming a
continuous circular shape called
Vascular Cylinder.
• Each year a new layer of phloem and
xylem are produced.
• Young dicotyledon stem
• Slightly older
• Older still
• After another year
– Now an older dicotyledon
• After a number of years
After a
number of
year..
 In the older stems the
epidermis is replaced by
bark.
 Over time, the stem and
roots thicken and the plant
becomes known as a Woody
plant (a tree).
Many years of xylem
Many years of phloem
• This is a cross section of a tree.
• It is about 30 year old.
• Wood that grows in the spring makes a light-colored ring and is
called spring wood (green dot).
• In the summer trees don't grow as much. Wood that grows in the
summer makes a dark-colored ring. It is called summer wood (white
dot).
• Summer wood and spring wood have different thickness'
depending upon weather conditions that year.
• 1 light-colored ring + 1 dark-colored ring = 1 year.
This is called a annual ring.
Heartwood and Sapwood
• The lighter colored wood still has
functioning xylem in it. It is called
sapwood.
• Annual rings can tell the
story of the tree. It can
also tell you how old a
tree is
• The older darker
colored wood, no longer
has xylem carrying
water in it. It is called
the heartwood.
Heartwood contains
tannins, resins, and
gums which make it
very hard and resistant
to insects and fungi.
Movement of Fluids
What type of tissue moves water
and food to all parts of a plant?
Vascular Tissue
What type of tissue carries the
water from the root to the leaves?
Xylem
What type of tissue carries food
(which is dissolved in water) from the
leaves to all other areas ?
Phloem
Translocation
This is the
movement of fluids
inside the plant.
• Water is pulled Transpiration
up through the
xylem much like
a straw.
• Then the water
escapes as
vapor through
tiny holes called
stomata.
• Water vapor
escaping
through a
stoma.
• Guard Cells
Overview of water movement
• Water enter the plant
through the roots.
• The water is translocation
through the plant to the
leaves by capillary action.
• The water is used in
photosynthesis and
converted to oxygen which
then escapes through the
stomata in the process of
transpiration.
Transpiration is a part of the Water
Cycle.
The Water Cycle – also know as:
Transport of Sugars
Plants create more
sugar than they need
Phloem moves the
sugars to the different
parts of the plant
Excess sugars are
stored as starch.
Some plants convert
starch to lipids like
peanuts, corn, and olives
Pulling it all together
Now that you have studied all the parts of the
leaves and all the tissues, study the diagram below
and be able to label it