Transcript Presentation

Slide 1
Structure
of
Plants
Slide 2
1.
2.
3.
A. Functions of Roots
Anchor & support
plant in the ground
Absorb water &
minerals
Hold soil in place
Root Hairs
Fibrous Roots
Slide 3
B. Root Types
Tap Root
1. Fibrous Roots:
2. Tap Roots –larger central
branching roots hold soil in
place to prevent soil erosion
root reaches deep water sources
underground
Ex. Grasses
Ex. Trees, Carrots, & Dandelions
Slide 4
C. The Structure of a Root
Root
Hairs
Phloem
Xylem
Meristem
Root
Cap
1. Root Hairs:
increase surface
area for water &
mineral
absorption
2. Meristem:
region where
new cells are
produced
3. Root Cap:
protects tip of
growing root
Slide 5
A. Functions of Stems
1.Support system for plant body
2.Transport system carries
water & nutrients
3.Holds leaves & branches
upright
Looking at the
Each light and dark
picture
the left:
tree ringtoequals
one
year of annual growth.
What
years
had
Light rings for fast
the
most
rain?
spring
growth,
dark for
slow summer growth.
What
Smalleryears
rings tell of
experienced
the
past droughts that
have occurred.
worst
drought?
Slide # 6
A. Functions of Leaves
1. Main photosynthetic organ
2. Broad, flat surface increases
surface area for light
absorption
3. Have systems to prevent
water loss
• Stomata open in day but
close at night or when hot
to conserve water
• waxy cuticle on surface
4. System of gas exchange
• Allow CO2 in and O2 out of
leaf
Elephant Ear Plant
Slide # 7
B. Leaf Structures
Leaf Cross-Section
1.Cuticle: waxy layer;
covers upper surface
Cuticle
2.Veins: transports
water, nutrients and
food
• Made of xylem and
phloem
3.Mesophyll: contains
cells that perform
photosynthesis
b/c they contain
Chloroplasts.
Mesophyll
• Protects leaf against
water loss
Veins
Stoma
(Opening)
2 Guard
Cells
Surround
each
Stoma
Stoma- singular
Stomata-plural
Slide # 8
More Plant Parts…
4. Guard cells:
• cells that open
and close the
stoma
5. Stomata: openings
in leaf’s surface;
when open:
•
•
GAS EXCHANGE:
Allows CO2 in & O2
out of leaf
TRANSPIRATION:
Allows excess H2O
out of leaf
Guard Cells
Stoma
Slide # 9
What
goes O2
out?
What
goes
in?
Stoma
Function of Stomata
•What process involves
Guard Cells
Guard Cells
using CO2 and H2O
H2O releasing O2 as a waste
product?
•Photosynthesis
CO2
Stoma Open
•What is the plant using this
processStoma
to make?
Closed
•Carbohydrates-glucose
•If the plant needs water for
photosynthesis, why is water
coming out of the stoma?
Slide # 10
Function of Guard Cells
•These stomata
(leaf
Guard Cells
openings) naturally allow
water to evaporate out.
Guard Cells
•Why would the plant close
stomata with guard cells?
•Prevent excess water loss
through transpiration.
(conserveStoma
water)Open
•So what is the point of
having stomata?
•Allow gas exchange for
photosynthesis
Stoma Closed
Slide # 11
C. Plants find a use for Transpiration
1. Transpiration: loss
of excess water from
plant leaves
2. Significance:
a. Transpiration causes enough
pressure to help pull water
(& required nutrients) up
stem from roots.
b. As part of the water cycle,
trees transpire water back into
the atmosphere.
c. Transpiration provides much
of the daily rain in rainforest.
A
B
A average size maple tree can
transpire 200 liters of water
per hour during the summer.
Transpiration is the #1 driving
force for pulling water up
stems from roots.
Slide # 12
Structure of a Flower
1.Pistil:female reproductive
structure
a.Stigma: sticky tip; traps
pollen
b.Style: slender tube;
transports pollen from
stigma to ovary
c.Ovary: contains ovules;
ovary develops into fruit
d.Ovule: contains egg
cell which develops into
a seed when fertilized
Stamen
Anther
Filament
Ovule
Stigma
Pistil
Style
Ovary
Petal
Sepal
Slide # 13
Structure of a Flower
2.Stamen: male
reproductive structure
a.Filament: thin stalk;
supports anther
b.Anther: knob-like
structure; produces
pollen
c.Pollen: contains
microscopic cells that
become sperm cells
Stamen
Anther
Filament
Ovule
Stigma
Pistil
Style
Ovary
Petal
Sepal
Slide # 14
Structure of a Flower
3.Sepals: encloses &
protects flower before it
blooms
Stamen
Anther
Filament
Stigma
Pistil
Style
Ovary
4.Petals: usually colorful
& scented; attracts
pollinators
Ovule
Petal
Sepal
Slide # 15
Cross Pollination
• How does pollination
happen?
• Pollen from an anther
is caught by the
stigma, travels
through style to the
ovules in the ovary.
• What is the result of
pollination?
• A Fruit: An ovary
containing seeds.
Slide # 16
Plant
Responses
and
Adaptations
Slide #17
Hormone Action on Plants
A. Plant cells can produce
hormones: which are
chemical messengers that
travel throughout the plant
causing other cells called
target cells to respond.
B. In plants, hormones
control:
Movement
of hormone
Hormoneproducing
cells
Target
cells
1. Plant growth &
development
2. Plant responses to
environment
Cells in one blooming
flower signals other blooms
using hormones to open.
Slide # 18
C. Plant cells will send signals
to one another to tell them:
1. When trees to drop their leaves.
2. When to start new growth.
3. When to cause fruit to ripen.
4. When to cause flowers to bloom.
5. When to cause seeds to sprout.
Tree
Budding
Fruit
Ripening
Cactus
Blooming
Leaf Drop
Sprouting
Corn Seeds
Slide # 19
D. Ethylene causes
Fruit to Ripen
1.Fruit tissues release a
small amount of ethlyene
2.Causes fruits to ripen.
3.As fruit become ripe, they
produce more and more
ethlyene, accelerating
the ripening process.
Ethylene released
by apples and
tomatoes causes
fruit to age quickly.
Slide # 20
Plant Tropisms
1. Tropism: the way a plant grows in response to
stimuli in the environment.
a.Phototropism: growth response to light
-Plants bend towards light
a.Geotrophism: growth response to gravity
-plant roots grow down with gravity, shoots (stems) grow
up against gravity and out of the soil.
a.Thigmotropism: growth response to touch
-vines grow up around trees, venus flytrap closes when
leaves are touched
Slide # 21
What type of tropism is shown in these pictures?
Examples
Nonvascular Plants
Any of various plants that lack vascular tissue; a
bryophyte.
Nonvascular plants include mosses, liverworts, and hornworts.
-These plants have no vascular tissue, so the plants cannot retain
water or deliver it to other parts of the plant body.
--The bryophytes do not possess true roots, stems, or leaves,
although the plant body is differentiated into leaflike and stemlike
parts. In some species, there are rootlike structures called rhizoids.
-With no vascular tissue, the bryophytes cannot retain water for long
periods of time. Consequently, water must be absorbed directly from
the surrounding air or another nearby source. This explains the
presence of mosses in moist areas, such as swamps and bogs, and
on the shaded sides of trees.
Nonvascular lifecycle
Vascular plants (also known as tracheophytes or higher plants) are those plants that have lignified tissues for conducting water, minerals, and photosynthetic products through the plant. Vascular pla
Vascular plants (also known as tracheophytes or
higher plants)
-are those plants that have lignified tissues for
conducting water, minerals, and photosynthetic
products through the plant.
-Vascular plants include the ferns, clubmosses,
flowering plants, conifers and other gymnosperms.
-Scientific names for the group include
Tracheophyta and Tracheobionta, but neither name
is very widely used.
Vascular tissue is a complex conducting tissue,
formed of more than one cell type, found in
vascular plants.
-The primary components of vascular tissue are the xylem
and phloem.
-These two tissues transport fluid and nutrients internally.
There are also two meristems associated with vascular
tissue: the vascular cambium and the cork cambium.
-All the vascular tissues within a particular plant together
constitute the vascular tissue system of that plant.
Seedless vascular
lifecycle
Gymnosperm
Gymnosperm (Gymnospermae) is a group of
spermatophyte seed-bearing plants with ovules on
scales,which are usually arranged in cone-like structures.
The term "gymnosperm" comes from the Greek word
gymnospermos (γυμνόσπερμος), meaning "naked seeds"
and referring to the unenclosed condition of the seeds,
since, when they are produced, they are found naked on
the scales of a cone or similar structure.
Often gymnosperms are used for economical uses and as folk medicines.
Some common uses for them are as soap, varnish, lumber, paint, food, and
perfumes.
There are between 700 and 900 species of
Gymnosperm.
Conifers are by far the most abundant gymnosperms
with around 600 species.
Cycads are the next most abundant group with about
130 species.
Approximately 75 - 80 species of Gnetales exist and only
one species of Ginkgo remains today.
Pteridosperms are sometimes used as a root.
Examples of gymnosperms include cypress, juniper, and — most
well known — pine, fir, and redwood. Included in this group are the
tallest trees, Giant sequoia, and the world's oldest living trees, the
Bristlecone pines that grow only on the North American continent.
Gymnosperm lifecycle
Classes of
Angiosperms
Monocotyledonae (Monocots)
– Very few are annuals
– Lilies, grasses, cattails, palms, yuccas,
orchids, irises
Dicotyledonae (Dicots)
– More primative, 1/6 are annuals
– Almost all kinds of trees and shrubs
– Snapdragons, mints, peas, sunflowers
Angiosperm lifecycle
Monocots
The Monocotyledonae comprise one-quarter of all flowering plant species.
-They include some of the largest and most familiar groups of plants,
including lilies, orchids, agaves, palms, and grasses.
-The monocots are quite diverse, ranging from tiny duckweeds to large
palms and climbing vines.
-Economically, monocots are perhaps the most important organisms on
earth. Our four most important foods -- corn, rice, wheat, and barley -- all
come from monocots.
-Bamboo and palms are a primary source of building materials and fibers
in many tropical countries. Sugar cane, pineapples, dates, bananas, and
many of our familiar tropical fruits also come from monocots.
Monocot
characteristics
Dicots
Dicotyledonous plants (dicots) are the second major group of plants within
the Angiospermae division (flowering plants with seeds protected in
vessels). The other major group is the monocots.
In contrast to monocots, dicots have an embryo with two cotyledons, which
give rise to two seed leaves. The mature leaves have veins in a net-like
pattern, and the flowers have four or five parts.
Apart from cereals and grasses that belong to the monocot group, most of
the fruits, vegetables, spices, roots and tubers, which constitute a very
important part of our daily diet, are classified as dicots. In addition, all
legumes, beverages such as coffee and cocoa, and a great variety of
flowers, oil seeds, fibers, and woody plants belong to the dicot group.
Dicot characteristics
MONOCOTS
DICOTS
Embryo with single cotyledon
Embryo with two cotyledons
Pollen with single furrow or pore
Pollen with three furrows or pores
Flower parts in multiples of three
Flower parts in multiples of four or five
Major leaf veins parallel
Major leaf veins reticulated
Stem vacular bundles scattered
Stem vascular bundles in a ring
Roots are adventitious
Roots develop from radicle
Secondary growth absent
Secondary growth often present
Annual- plants that live for only one year or less.
They sprout from seeds, grow, reproduce ,and die
in a single growing seasons.
Examples: marigolds, impatients, panseys
Biennial- plants have life spans that last for two
years. Many have large storage roots. During the
first year the plant grows leaves and develops a
strong root system. Over winter the above ground
portion dies back but the roots remain alive. During
the second year the storage root produces new
shoots.
Examples: carrots, beets, turnips
Perennials
Live for several years and produce flowers and
seeds. Normally at least once each year.
Many have woody stems. They also can have
underground storage systems.
Examples: Lilies, Brambles, Iris