Download Plants

Flowering
Cone-bearing plants
plants
Ferns and
Flowers; Seeds
their relatives
Mosses and
Enclosed in Fruit
their relatives
Seeds
Plants
Chapters 22-25
Water-Conducting
(Vascular) Tissue
Green algae
ancestor
*FYI: GREEN ALGAE is believed by most scientists to be the
ancient ancestor of land plants
What three characteristics do they share in common?
What is a PLANT?
•
•
•
•
•
Members of Kingdom Plantae
Multicellular eukaryotes
Cell walls made of cellulose
Undergo photosynthesis (autotrophic)
Include trees, shrubs, grasses, mosses,
and ferns
Plant Requirements
• Sunlight (energy to carry out photosynthesis)
• Water (must have water in all cells; important for
photosynthesis)
• Movement of Water and Nutrients (water and
minerals taken up through roots/ food made in
leaves)
• Minerals (needed for growth and development)
• Gas Exchange (require CO2,carbon dioxide, for
photosynthesis and require O2 oxygen for
respiration)
Problems plants had adapting to
life on land:
•
•
•
•
1) Preventing WATER LOSS.
2) Obtaining enough FOOD and WATER.
3) Dealing with WIND and WEATHER.
4) Exposed GAMETES and EMBRYOS.
*FYI: The first plants are believed to have
been spore producing plants, MOSSES
AND FERNS
FERN
MOSS
GREEN
ALGAE
Early Plants
• Origins
– Evolved from plant-like protists (algae)
– Many plants evolved from water-dependent
plants that only lived in watery environments
• *MOSSES (BYROPHYTA) &
FERNS (PTEROPHYTA) will always be
found near water or in very moist areas,
because the sperm, found in spores,
need a film of water in order to
Attach to the egg, which also
are found in spores
Spores from mosses and
ferns contain SPERM OR EGG
Section 22-2
MEIOSIS
Antheridia
= sperm
Spores
(N)
Protonema
(young
gametophyte)
(N)
Male
gametophyte
Female
gametophyte
Mature
sporophyte
(2N)
Archegonia
= egg
Capsule
Antheridia
(sporangium)
Gametophyte
(N)
Young
sporophyte
(2N)
Sperm
(N)
Archegonia
Zygote
(2N)
Gametophyte
(N)
Sperm
(N)
Egg
(N)
FERTILIZATION
Go to
Section:
Figure 22–11 The Life Cycle of a Moss
*FYI: Plants are sometimes grouped together
based upon common characteristics…
• 1st) Are they SPORE producing or SEED
producing?
• 2nd) Are they VASCULAR OR NONVASCULAR
– *VASCULAR (plants that have vascular tissues
that transport water up and food down their
stems).
– *NON-VASCULAR (plants do not have vascular
tissues OR stems).
Simple vs. Vascular & Complex Plants
• The plant kingdom include complex plants,
vascular plants, and simple plants that are
not vascular.
• Vascular plants have vascular tissue:
tubes that carry water and nutrients
throughout the plant. The simple plants do
not have vascular tissue. Simple plants
are unusually small.
• *FYI: MOSSES are
the only nonvascular
plants on earth!
Kingdom Plantae
• There are 4 Divisions (aka, phyla) you need to know…
• 1) BRYOPHYA (aka, MOSSES)
• 2) PTEROPHYTA (aka, FERNS)
• 3) CONIFEROPHYTA (aka, CONIFERS or
GYMNOSPERMS)
• 4) ANTHOPHYTA (aka, FLOWERING
PLANTS or ANGIOSPERMS)
4 Phylums
•
•
•
•
Section 22-1
1. Mosses and their relatives
2. Ferns and their relatives
3. Cone-bearing plants
4. Flowering plants
Flowering
plants
Cone-bearing
plants
Ferns and
their relatives
Flowers; Seeds
Enclosed in Fruit
Mosses and
their relatives
Seeds
Water-Conducting
(Vascular) Tissue
Green algae
ancestor
Go to
Section:
Figure 22–6 A Cladogram of Plant Groups
Bryophytes - Mosses
• Most common
• Grow in swamps, near streams and in
tropical rain forests
• Tolerate low temps
• Miniature evergreen trees  small carpet
like filaments
Bryophytes - Mosses
•
•
•
•
Depend on water for reproduction
Lack vascular tissue
Draw up water via osmosis
Include the following phyla:
mosses, liverworts, and hornworts
Bryophyte Structure
Capsule
Stalk
Sporophyte
Stem-like structure
Gametophyte
Leaf-like structure
Life Cycle of Bryophytes
• The gametophyte is dominant and the
photosynthetic stage
• Must have water for fertilization to occur
(sperm must swim to egg)
• Mosses make up part of the bryophytes
(nonvascular plants. They live in moist
shady places and need little soil. There are
separate male and female moss plants.)
• The Zygote generation in mosses grows on
top of the female plant. It produces spores
from a capsule at the top.
• Mosses are important to the soil. They
make new soil by breaking down rock.
Sphagnum moss is an important fertilizer
and sometimes used as fuel.
Sphagnum Moss
• Can accumulate to form
peat moss that can be
used in gardening.
•It helps the soil retain water.
•Peat also has a low pH, so it
can add to the soil’s acidity.
• Plants like azaleas,
grow well only if they are
in this type of soil.
Liverworts
• Liverworts are flat, scaly
bryophytes. The liverwort alternation of
generations is similar to that of mosses.
Sometimes they reproduce by a
combination of budding and regeneration.
• Named due to the shape of the leaves
• Produce sexually and asexually
Hornworts
• Found in damp soil
• Look like liverworts but smaller
*Basic characteristics of plants:
•
•
•
•
1) MULTICELLULAR
2) EUKARYOTIC (HAVE ORGANELLES)
3) AUTOTROPHS
4) CELL WALLS CONTAIN CELLULOSE
*Plants have organs…
• 1) Leaves- trap SUNLIGHT for
PHOTOSYNTHESIS Food (i.e., glucose) is
made here and transported to the rest of the
plant.
• 2) Stems- support UPRIGHT growth, transport
WATER up from the roots through a special kind
of vascular tissue called XYLEM, and FOOD
down to the rest of the plant through another
kind of vascular tissue called PHLOEM
Gas in…. CO2
O2
and
H Og
2
…. Gases OUT
*FYI: the evolution of vascular tissue allowed plants
to grow big and tall and live away from WATER.
• 3) Roots- ANCHOR the plant to the
ground, ABSORB water and minerals,
and sometimes STORE excess sugar as
starch.
• 4) Flowers- REPRODUCTION organs for
angiosperms
• 5) Cones- REPRODUCTIVE organs for
gymnosperms.
Nitrogen Fixation
• *FYI: Plants need NITROGEN to live, but
cannot use the N2(g) in the atmosphere as
it is. So, they have evolved a symbiotic
relationship With
BACTERIA which “fix”
the nitrogen for plants and
turn it into nitrates
through a process called…
NITRIFICATION.
*Environmental factors that affect plants:
• 1) Light (aka, PHOTOTROPISM)
• 2) Gravity (aka, GRAVITROPISM)
• 3) Winter - Plants become inactive (aka,
DORMANT)
• *FYI: POSITIVE tropism means that the
plant grows toward or with the
environmental factor. NEGATIVE tropism
means that the plant grows away from the
environmental factor.
• END OF FIRST TWO PAGES
OF PLANT BOOK
The Plant Life Cycle
• Characterized by alternation of
generations
• One generation is gametophyte (haploid)
• Other is sporophyte (diploid)
Alternation of Generations
Haploid (N)
Diploid (2N)
MEIOSIS
Gametophyte Plant (N)
Sporophyte Plant (2N)
FERTILIZATION
Tracheophytes
• Tracheophytes include all of the
vascular plants. The
tracheophytes include ferns and
seed plants. Ferns and seed
plant have vascular tissue and
roots, stems, and leaves.
What are Vascular Plants?
Plants with Vascular Tissue
• Vascular Tissue  move fluids through
the plant body
– 1. Xylem– carries water from the root to the
other parts of the plant
– 2. Phloem – transports
nutrients and carbohydrates
made by photosynthesis
Seedless Vascular Plants
•
•
•
•
Have roots, leaves, and stems
Reproduce by Spores
INCLUDES:
Club Mosses- small plants that live
in moist woodlands
• Horsetails – have wispy leaves
• Ferns – thrive in areas with little light and
much water
Seed Plants
• Seed plants are different form all simple
plants, algae, mosses, and ferns because
they make seeds. A seed contains a tiny
new plant and food supply. There are two
kinds of seed plants.
• Reproduce without water
• Please hand out
notes
nd
2
part of
Seed plants
• Two groups:
– 1. Gymnosperms
• Bear seeds on surface of cones
– 2. Angiosperms
• Flowering plants (seeds deep inside for protection)
Pollen
• Male gametophyte
• Carried by wind, insects, birds, small
animals, and bats
• Transfer of pollen to the female
gametophyte is called pollination
Gymnosperms
Cone-Bearing Plants – Conifers
• Cone-bearing gymnosperms are conifers.
• Conifers have needles for leaves
• and are called “evergreens” because they
stay green with needles all their life.
• Conifers produce spores in both male and
female cones.
Examples of Gymnosperms
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•
•
•
Gnetophytes
Cycads
Ginkgoes
Conifers
Angiosperms
•
•
•
•
Unique reproductive organs (flowers)
Flowers contain ovaries (protect the seed)
Fruit (tissue that surrounds the seed)
Very diverse group which includes:
– monocots and dicots
– Woody and herbacious plants
– Annuals, biennials, perennials
Monocots and Dicots
• Named for number of seed leaves
(cotyledons) in the plant embryo
• Monocots  one seed leaf
– Ex. Corn, wheat, lilies, orchids, and palms
• Dicots  two seed leaf
– Ex. Roses, clover, tomatoes, oaks, and
daisies
Woody and Herbaceous Plants
• Based on the stems
• Woody plants include  trees, shrubs,
and vines
• Herbaceous plants include  dandelions,
zinnias, petunias, and sunflowers
Annuals, Biennials, and Perennials
• Annuals  life cycle in one year
– Ex. Pansies
• Biennials  complete life cycle in two
years
– Ex. Foxglove
• Perennials  live for more than two years
– Ex. Azaleas
Chapter 23
Roots, Stems and Leaves
Monocot
Seed
Single
cotyledon
Dicot
Two
cotyledon
Leaves
Parallel
veins
Branch
veins
Flower
parts in multiples
0f 3
Parts in multiples of
4 or 5
stems
Roots
Vascular bundles
scattered throughout
the stem
Fibrous Roots
Vascular bundles
arranged in a ring
Taproot
Structure of Seed Plants
• Three principal structures:
– 1. Roots
• Anchor plant & Absorb water and nutrients
– 2. Stems
• Supports plant body & Transports nutrients
– 3. Leaves
• Part where photosynthesis occurs
• Pores in leaves control gas exchange
Tissue Systems
• Four types:
– 1. Dermal Tissue
• Outer most layer
• Like the “SKIN”
– 2. Vascular Tissue
• Transport of water and minerals
• Like the “BLOOD STREAM”
– 3. Ground Tissue
• Everything else
– 4. Meristematic Tissue
• At the tips of shoots and roots
Leaves
• Designed for absorbing light and carrying
out photosynthesis
• Two types of leaves:
– 1. Simple (one leaf)
– 2. Compound (many leaflets)
Leaf Functions
• Photosynthesis
– mesophyll layer is composed of many chloroplasts
– Palisade mesophyll – absorb the light
– Spongy mesophyll – air spaces that connect the stomata with
outside
– Stomata – pore-like openings on the underside of a leaf to
absorb carbon dioxide
• Transpiration
– Loss of water from a plant through leaves
• Gas Exchange
– Stomata remains open enough just to allow
photosynthesis to take place
Chapter 24
Reproduction in Seed Plants
Pin oak
Dandelion
Eastern
white pine
With Cones and Flowers
• Alternation of Generations
• Gymnosperms:
– Reproduction occurs in cones
• Two types:
– 1. Pollen Cones – produce male gametophytes called
pollen grains
– 2. Seed Cones- produce female gametophytes (ovules)
Flowers
• Composed of 4 kinds of specialized leaves:
– 1. Sepals
• Outermost
• Green and look like little leaves
• Enclose bud before it opens
– 2. Petals
• Often brightly colored
• Attract insects and pollinators
• Also called sterile leaves because no reproductive part
Flowers (continued
)
• 3. Stamens
– Male parts
– Consist of the anther (where meiosis takes
place) and filament (supports anther)
• 4. Pistil (aka carpel)
– Inner floral part
– Each carpel has a broad base forming the
ovary
Fruits
• As angiosperms mature, the ovary walls
will thicken to form a fruit
• ex. Apples
• May be fleshy, tough, may have a pit
(where seed is attached to ovary)
Chapter 25 – Plant Responses
and Adaptations
25-1 Plant Growth
• Plant cells send signals to one
another to indicate
–when to divide,
–when not to divide,
–and when to develop into a new
kind of cell.
Meristems –
• Regions of tissue that can
produce cells to later develop into
specialized tissues (Found at
growing stems and roots)
Plant Hormones
• Plant hormones control the plant’s growth
and responses to environmental
conditions.
• Auxins – substances regulate cell growth
at the tip of plant by stimulating cell
elongation.
Figure 25-2 Hormone Action on
Plants
Section 25-1
Hormone-producing cells
Movement of hormone
Target cells
Phototrophism
• – tendency of a plant to grow
towards light
• auxins build up on the shaded
side of the plant
Gravitropism
• tendency of a plant to grow in a direction
in response to gravity
• Auxins build up on the lower sides of the
roots and stems
• Stems grow up (cell elongation)
• Roots grow down (inhibit cell growth &
elongation)
Cytokinins
• – Produced in growing roots and
developing fruits and seeds.
• Stimulate cell division, growth of
lateral buds, and cause dormant
seeds to sprout.
• Instead of cell elongation, cells
grow thicker.
Gibberellins • Growth promoting substance
produced by a fungus or the plant
• dramatic increase in size (stems
and fruits)
Ethylene
• In response to auxins fruit tissues
release small amounts of
hormone
• Stimulate fruits to open.
25-2 Plant Responses
• Tropisms – responses of plants to
environmental stimuli
• Gravitropism – response of plant to gravity
– Ex. Shoot of germinating seed to grow out of the soil
and roots to grow into soil.
• Phototrophism – grow toward a light source.
• Thigmotropism – responses of plant to touch can
stunt growth
– Ex. Growth of vines and climbing plants to wrap
around things.
Photoperiodism
• Plants respond to periods of light
and dark.
• Responsible for timing of
seasonal activities such as
flowering and growth.
• Short-day vs. Long-day Plants –
Flowering times
Short-day vs. Long-day Plants –
Flowering times
Short-Day Plant
Midnight
Noon
Long Day
Midnight
Noon
Short Day
Midnight
Noon
Interrupted Night
Long-Day Plant
Winter Dormancy
• – growth and activity decreases or stops
25-3 Plant Adaptations
Aquatic Plants
• Tissues with large air filled spaces for
oxygen diffusion
Salt-Tolerant
• Special tissues to pump out salt onto leaf
surfaces, washed away by Rain
Desert Plants (Xerophytes)
• – Extensive roots, reduced leaves, & thick
stems stores water.
Nutrition Specialists
• Live in areas with low concentrations of
nutrients in the soil.
• Ex. Carnivorous plants (Venus Fly Trap)
• Parasites (Mistletoe)
Epiphytes
• Grow directly on other plants to obtain
their nutrients Ex. Spanish Moss
Chemical Defenses
• manufactured by the plant itself to protect
it from insects.
Compare/Contrast Table
Section 25-3
Comparing Carnivorous Plants, Epiphytes, and Parasites
Characteristics
Carnivorous
Plants
Epiphytes
Parasites
Environment
bog
host plant
host plant
Method of
obtaining
nutrients
leaves that trap
gather moisture
and digest insects from rainfall and
produce their own
food
extract moisture
and nutrients from
host plant
Examples
pitcher plant,
sundew, Venus’
flytrap
dodder, mistletoe
Spanish moss,
orchid
Plant Quiz Review
E
A
F
B
G
C
H
D
I
Label each part:
Petal
Sepal
Stamen
Anther
Filament
Pistil
Stigma
Style
Ovary