Transcript Plant Kingdom

Chapter 22-25:
Plant Kingdom
Multicellular
 Eukaryotes
 Autotrophs carry out
photosynthesis
 Thick cell walls made of
cellulose
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Probably evolved from green algae
 Both have cell walls of cellulose
 Both have same type of chlorophyll
 Both store food as starch
1st plants appeared 440 million years ago
(simple structures and no leaves)
Plants need 5 things to survive:
Water
 Sunlight
 Minerals
 Gas exchange
 Transport of water and nutrients
through plant body
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Cuticle
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waxy waterproof
coating
Made of lipids (do
not dissolve in
water)
Helps prevent
water loss from
plant
Leaves
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Traps light
energy
Grows from a
stem
Where
photosynthesis
occurs
Roots
Absorb water and
minerals from the
soil
 Helps transport
nutrients to the
stem
 Helps anchor plant
to the ground
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Stems
Provides support for
growth
 Contains tissues that
help transport food,
water, and other
materials throughout
the plant
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Vascular tissue
 Tubelike, elongated
cells
 Transports water,
food, and other
materials
 Can be food storage
organs
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Seeds
Contain an
embryo and food
supply
 Covered by a
protective coat
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Alternation of Generations
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Lives of plants include 2 stages
 Development of gametes (sex cells)
 Haploid cells (n)
 Gametophyte stage
 Antheridium: male structure
where sperm is produced
 Archegonium: female structure
where eggs are produced
Fertilization
 Diploid cells (2n)
 Produced by mitosis
 Sporophyte stage
 Production of spores
Parenchyma
Most abundant cells
with thin, flexible
cell walls
 Found throughout
the plant
 Function in storage
and food production
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Collenchyma
Long cells with
unevenly
thickened cell
walls
 Provide strength
and support
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Sclerenchyma
Thick, rigid
cells
 Provide
support for the
plant
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Epidermis
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Tissue: group of cells that work together
Epidermis (Dermal tissue): composed of
flattened parenchymal cells
Covers and protects the body of plant
Produce cuticle to protect plant from water loss
Stomata:
 Allows evaporation of water by diffusion
 Openings in leaf tissue (pores on underside of leaves)
 Control exchange of gases
 Found on stems and surface of leaves
 Transpiration: loss of water through stomata
 Controlled by guard cells
 Open and close stomata
Closein presence of less water
 Open in presence of a lot of water
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Ground Tissue
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photosynthesis, storage,
support
Meristem Tissue
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region of
actively dividing
cells
Vascular Tissue
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xylem and phloem
Classifying
Plants
Grouped into divisions
instead of phylums
 Plants placed into 2 groups
Non-seed plants
Seed plants
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Non-Seed Plants
can be vascular or
nonvascular
 Produce hardwalled reproductive
cells called spores
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Bryophytes
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mosses, liverworts, hornworts
Life cycles depend on water for
reproduction
Lack vascular tissue (nonvascular
plants)
Low-growing plants: draw up
water by osmosis and diffusion
Found in moist, shady areas
Small in size
Must have water for reproduction
No seeds or flowers
Tracheids/Tracheophytes
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Ferns, club mosses, horsetails
Seedless, vascular plants
Tracheidshollow cells with a thick
cell wall
Allows water to move through a plant
Xylem: carries water from roots up to
entire plant
Phloem: transports nutrients and
carbohydrates
Found in moist habitats
No seeds or flowers
Seed Plants
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Produce seeds
Water not needed for
reproduction
Has vascular tissue
Divided into 2 groups
Gymnosperms- “Naked Seeds”
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Seeds on surface of cones
(exposed seeds)
Ex: conifers (pine, spruce),
cycads, ginkgo
Reproduce with exposed seeds
 Pollination done through
wind, insects, or small
animals
Cones: seed-bearing structures
Angiosperms – “Covered Seeds”
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Flowering plants (240,000
species)
Dominant plant life
Develop flowers  unique
reproductive organs
 Effective in successful
pollination
 Contain ovaries which
surround and protect the seed
 Attract pollinators
Fruit
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Wall of tissue
surrounding the seed
Ripened ovary of a flower
Used to attract animals
 Eat fruit and then
deposit seeds at great
distances
Categories of Angiosperms
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Monocots vs. dicots: named
for # of seed leaves
(cotyledons)
 1 seed leaf (mono-) vs. 2
seed leaves (di-)
 Monocots corn, wheat,
lilies, orchids, grasses
 Dicots  roses, clover,
tomatoes, daisies
Categories of Angiosperms
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Herbaceous plants vs.
woody plants
 Smooth, nonwoody stems
vs. thick, woody stems
 Herbaceous 
dandelions, zinnias
 Woody  trees, shrubs,
vines
Categories of Angiosperms
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Plant life spans
 Annual (1 year)
 Pansies, wheat, cucumbers
 Biennial (2 years)
 Parsley, celery, carrots, beets, turnips
 Perennial (more than 2 years)
 Peonies, asparagus, grasses
Roots
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Absorb water and dissolved nutrients
Anchors plant
Root hairs
 Extensions of individual cells
 Help roots absorb more water and
nutrients
 Hair-like extensions
 Increase surface area of roots
 Trichomes: hairlike projections
 Give stem or leaf a fuzzy appearance
 Help reduce evaporation of water
2 Kinds of Roots
Taproots
 Fibrous roots
 Root cap: covers tip
of each root
 Xylem and phloem
are in center of root
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Stems
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Support system
Hold leaves up towards sunlight
Produce leaves, branches, and
flowers
Transport system  carries
nutrients between roots and
leaves
Protects plant against predators
and disease
Leaves
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Main photosynthetic organ
Helps plant absorb sunlight
Mesophyll tissue
 Where most chloroplasts are found
 Where photosynthesis takes place
Leaf veins
 Transport water and inorganic
compounds into the leaf
 Transports organic compounds away
from leaf to other parts of plant
 Products of photosynthesis  glucose
Chapter 22-25 Review #1:
1. Bryophytes are plants that lack ____.
a. a haploid generation
c. vascular tissue
b. cell walls
d. chlorophyll
2. The function of the xylem is to ____.
a. carry water
c. carry out photosynthesis
b. carry nutrients and carbohydrates
d. store minerals
3. Plants rely on phloem tissue for the transport of
_____.
a. chlorophyll
b. water
c. nutrients and carbohydrates
d. sperm and egg cells
Reproduction
of Seed Plants
Flowers
reproductive organs
 Composed of 4 types of specialized
leaves
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Sepals
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Outermost circle of
floral parts
Green
Closely resemble
leaves
Protect flower while
it is developing
(under petals)
Petals
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Brightly colored
Found inside the
sepals
Attract insects and
other pollinators
Stamens
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Male reproductive
parts
Anther and
filament
 Anther:
produces pollen
(contains sperm)
Carpels
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(sometimes called a
pistil)
 Female
reproductive
parts
Ovary, stigma, style
 Ovary: has ovule
(contains egg)
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Pollen: male
reproductive cell or
gamete
Pollination: transfer
of pollen from the
male reproductive
structure to the
female reproductive
structure
Seed and Fruit Development
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Fruit: ripened ovary
 Contains seed
enclosed inside an
ovary wall
 Ex: peas, corn,
beans, rice,
cucumbers
Seed Dispersal
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Animals
 Seeds covered in
tough coating
 Can pass
through digestive
tract
 Sprouts in feces
Wind and water
 Usually lightweight
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Dormancy
 Embryo is alive
but not growing
Seed germination
 Early growth stage
of an embryo
 Seeds absorb
water to crack
open seed coat
Chapter 22-25 Review #2:
1. What is the thick wall of tissue that surrounds a
seed called?
a. fruit
b. cotyledon
c. sporangia
d. protonema
2. An embryo is alive but not growing during ___.
a. vegetative reproduction
b. dormancy
c. germination
d. pollination
3. The early stage of growth in which a seed
absorbs water, causing the seed coat to crack
open is called _________.
a. dormancy
b. grafting
c. germination
d. dispersal
Hormones and Plant Growth
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Meristem: regions of
tissue that can produce
cells that will develop
into specialized tissue
 Source of plant
growth
Plants grow in response
to environmental factors
 Light, moisture,
temperature, gravity
Plant Hormones
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Substances produced in one part of plant that
affects another part
Controls patterns of growth and development
and responses to environmental conditions
Auxins: stimulate cell elongation and cell
division
Cytokinins: stimulate cell division
Gibberellins: stimulate an increase in size
Ethylene: stimulates fruit to ripen
Plant Responses
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Tropisms: responses of
plants to external
environmental stimuli
Gravitropism: response
of a plant to force of
gravity
 Shoots grow out of
the soil
 Roots grow into the
soil
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Phototropism:
response of a
plant to light
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Thigmotropism:
response of
plants to touch
Nastic Movement
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movement of a
plant not based on
the direction of a
stimulus
 Ex: Venus
flytrap
Photoperiodism
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response of plants to difference in
the amount of light and dark
periods in a day
Plant Adaptations
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Aquatic plants: have tissues with large
air-filled spaces to allow oxygen to
diffuse
Salt-tolerant plants: leaves with
specialized cells that pump salt out of
leaves
Desert plants: extensive roots, reduced
leaves, thick stems to store water, and
dormant seeds
Plant Adaptations
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Carnivorous plants: leaves to trap
and digest insects
Parasites: ex. Mistletoe
Chemical defenses: can be poisonous
Chapter 22-25 Review #3:
1. Name 3 types of plant tropisms and what each
type responds to.
2. Describe a hormone.
3. A plant’s response to periods of light and
darkness is called _________________.