Transcript Kingdom Plantae

Kingdom Plantae
AP BIOLOGY
Why are Plants needed?
What are some
characteristics of the
kingdom Plantae?
Describe a plant’s life cycle.
What do plants need in
order to survive?
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50-90% of all
photosynthesis
Most live in water
Unicellular, colonial,
or multicellular
Green algae are in
the phylum
Chlorophyta
Ancestor of green
plants
Ex. Chlmydomonas
Alternation of Generations
 Gametophyte is the dominant generation
 Single celled Chlorophyta are considered protists.
Multicellular Chlorophyta are plants. Ex. Ulva
and spirogyra
Phylum Bryophyta
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Nonvascular plants
Mosses, liverworts, and hornworts.
First land plants
Tied to water for reproduction
Gametophyte is dominant. Sporophyte
grows from the top of the gametophyte.
Male reproductive structure-antheridia
Female- archegonium
Phylum Pteridophyta
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Ferns
Dominant generation is the
sporophyte
They lack seeds
Reproduction occurs by spores
spreading
Horsetails
Ferns
The Origin of Vascular PlantsRequirements
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Seeds for reproduction- protect the
developing embryo.
Vascular tissue- xylem carries water and
phloem carries products of
photosynthesis
Phylum Tracheophyta- gymnosperms
and angiosperms
Ferns
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Leaves are called fronds
Spores are under the frond in the sorus
Attached to ground by the rhizome and
rhizoids, which are root like structures
Dominant generation is the sporophyte
Lifecycle of a fern
Tracheophytes are divided into
gymnosperms and angiosperms
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The seeds of gymnosperms(conifers,
cycads, and ginkos), are called naked
seeds. Seeds are on the cones of conifers.
Male cones are smaller than female
cones and usually occur on the same
tree. Males have microsporangia and
females have megasporangia.
Flower whorls
Angiosperms are flowering
plants
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1)
2)
3)
Gametocyte is found in the flower.
The flower is made of layers.
Outermost whorl of a flower is called
the sepal. It encloses and protects a
developing flower.
Second whorl forms the flower petals.
3rd whorl forms the male gamete.
The male gamete is made of a filament
and an anther containing pollen. It is
called the stamen.
4) The 4th whorl is the female gamete. It is
called the pistil or carpel. The pistil has
a sticky top called a stigma, and tube
for the pollen to travel through called
the style, and the ovule in the ovary.
When pollination occurs, the seeds are
covered with a seed coat for protection.
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The ovary develops into a fruit to nourish the
embyro. It also aids in seed dispersal.
Seed dispersal occurs through wind, water, or
animals(vector). The ripe fruit eaten by
animals, helps seeds become dispersed.
Coevolution-plants and animals
evolved together.
Major divisions of angiosperms
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Monocots
Veins in leaves are
parallel
Flower parts of 3s
Vascular bundles
scattered in stem
Vascular bundles
alternate in circle in
root
Stems don’t get thicker
from year to year
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Dicots
Branching veins in
leaves
Petals in 4s or 5s
Vascular bundles in
rings in stems
Vascular bundles
arranged in X in
roots
Stems thicken from
year to year
3 categories of plant life spans
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Annuals- have to be planted every year.
Ex. Corn, petunias
Biennials- 2 year cycles. Ex. Carrots.
The carrot will grow in one year. It
takes 2 years for seeds to form.
Perennials-grow for many years. Ex.
Holly
Plants
Fertilization in angiosperms
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Double fertilization
1 sperm fertilizes the egg to form a
zygote
The other fertilizes 2 polar bodies in the
embryo sac to form an endosperm. The
endosperm is rich in food to nourish the
embryo.
Plant organs
Dermal tissue- outer covering with a waxy
cuticle
 Vascular tissue- conducts
 Ground tissue- anything that isn’t dermal
or vascular. Surrounding vascular=cortex
Inside vascular=pith
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Plant tissues
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Roots, stems, and leaves needed to live
on land.
Vascular tissue is xylem and phloem
Veins are arranged into vascular
bundles.
Meristematic tissue is the only plant
tissue that divides by mitosis.
Plant cells
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Parenchyma cells- most abundant;
metabolism
Collenchyma- support growing parts of
plants
Schlerenchyma- dead; support
Xylem and phloem
Vascular Tissue
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Xylem- made of vessel elements, which are
wide and must die before they conduct water,
and tracheids, which are long and narrow and
also must die to work.
Phloem- made of sieve tube elements with
many holes in them and companion cells,
which surround and control sieve tube
elements. Sugars move from the sugar source
to the sugar sink by diffusion.
Types of Meristematic Tissue
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Apical meristem-allows trees to grow
taller
Cork cambian- allows stems to thicken
Vascular cambian- allows new vascular
tissue to form.
Pericycle- allows roots to grow.
Phloem
cells
Xylem cells
Plant Classification
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Bryophyta- mosses, liverworts, and
hornworts.
Pteridophyta- ferns and horsetails.
Coniferophyta- conifers. Cycadophytacycads. Ginkophyta- ginkos
Angiospermophyta, class
Monocotyledoneae (irises, lillies, corn,
wheat, bananas, etc) and class
Dicotyledoneae (trees, shrubs, and most
fruit trees)
Natural Perspective: Dicots (Class
Dicotyledoneae)
Roots
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Taproots- long, thick primary root with tiny
roots hairs. Found in oak and hickory trees,
carrots, dandelion, beets, and radishes.
Fibrous roots- Found in grasses and many
trees.
Roots have 3 tissue layers- 1) Epidermisoutermost. 2) Cortex- transports water and
nutrients inward. 3) vascular cylindercontains xylem and phloem.
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4 root tip sections
Root cap- protects the root and secretes
CO2, which forms carbonic acid. This
acid dissolves soil and allows the root to
push through the soil
Meristematic region- growth/mitosis
Region of elongation- meristematic cells
form this region, where root cells
increase in length, new protoplasm
forms, and vacuoles get larger.
4) Zone of maturation- differentiation
occurs, forming the mature tissues,
xylem, phloem, and the root hairs.
Leaf cross section
Leaves
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Cuticle- waxy layer. Keeps water from
evaporating.
Epidermis- thin layer that light passes through
Palisade mesophyll- columnar cells with
chloroplasts for photosythesis.
Spongy mesophyll- loose layer of cells that
photosynthesis occurs in. CO2 can move
through this layer.
More of the leaf
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Xylem and phloem take water and
minerals into the leaf and nutrients out.
Stoma (stomata) open and close to let
CO2 in and O2 out of the leaf. It has to
balance the need for CO2 with the cost of
water loss. Guard cells control the
opening and closing of stomata.
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Water moves in through the root hairs,
through the epidermis and cortex. A
Casparian strip divides the cortex and
vas. Cylinder. Once water moves
through the Cas. Strip, it can’t move
back out. This is called root pressure
and is one way that water moves through
a plant.
Water movement in plants
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Root pressure- moves water a short
distance.
Capillary action- combination of
adhesion and cohesion. Short distances
only.
Transpirational pull- as water
evaporates through the leaves, more
water moves into those cells by osmosis.
This can pull water up a tall tree.
Stems
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Stems hold leaves up to the sun and
conduct substances between roots and
leaves.
Plant Hormones
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Auxins- produced in the apical meristem and
move downward. They stimulate cell
elongation. They are also responsible for
response to gravity. Roots grow downward,
stems grow upwards. Auxins inhibit growth
of lateral buds.
Cytokinins- stimulate cell division and the
growth of lateral buds, and cause dormant
seeds to sprout. Root growth.
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Gibberellins- produce dramatic
increases in size, particularly in stems
and fruits. Seed germination, fruit
development, and leaf growth.
Ethylene- in response to auxins, fruit
tissues release small amounts of this
gas. This in turn stimulates the fruit to
ripen.
Absisic acid- inhibits growth and
promotes dormancy.
Photoperiodism
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It is responsible for the timing of
seasonal activities such as flowering and
growth.
Some plants are short-day plants, some
are long-day plants. Some flowers open
in the day, others only at night.
Plant responses
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Tropisms- response to external stimuli.
There are several types.
Gravitropism- roots grow down(positive
gravitropism) and shoots grow up(negative).
Phototropism- plants grow towards light.
Thigmotropism-response to touch. Some will
have their growth stunted, some will twist to
avoid touch, others will grow tendrils into an
object.
Soil Profiles
SOIL
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A mixture of sand, silt, clay, and bits of
decaying animal and plant tissue.
Humus- dead plants and animals
Topsoil- made of humus, sand, clay, and
minerals. Lots of air spaces.
Subsoil- mixture of rocks and inorganic
soil particles. There is little air here.
Bedrock- solid, can’t be penetrated by
plant roots.
Essential Nutrients
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Plants need carbon dioxide, water, and
inorganic nutrients to grow.
The most important inorganic nutrients are
nitrogen, phosphorus, calcium, magnesium,
and other trace elements.
For example: nitrogen is needed for leaf
growth and color. Phosphorus is needed for
making DNA, roots, stems, flowers, and seeds.
Reproduction in angiosperms
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One pollen grain joins with the egg to
form an embryo.
Another pollen grain joins with the polar
nuclei to form the endosperm. The
endosperm gives nutrients and moisture
to the embryo until it germinates.
Plant propagation and
agriculture
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Cuttings
Grafting
Budding
All of these allow plants to grow without
fertilization.
Fertilization and seed dispersal
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Both can occur by wind, water, and
animals( vector)
Fertilization is transfer of sperm or
pollen to eggs.
Seed dispersal is dispersal of seeds away
from the parent plant for growth. This
prevents competition with the parent for
nutrients, sunlight, and water.
AP Additions
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Stems are made of nodes (point of leaf
attachment) and internodes (between
nodes)
Axillary buds form between the node
and stem and may form branches
Terminal bud is at the top of a stem
Leaves are made of blades (flat) and
petioles (where leaves join the stem)
Tissue types in the leaf, stem, and
root
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Dermal tissue- single layer that covers
the plant
Vascular tissue- xylem and phloem
Ground tissue- anything that isn’t
dermal or vascular. Internally to
vascular tissue-pith. External to
vascular tissue- cortex
3 cell types
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3.
Parenchyma- photosynthesis and other
metabolism
Collenchyma cells- grouped in cylinders
for support.
Schlerenchyma- fibers for support on
non-growing parts of plants.
Tree Bark
Terms
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Turgor pressure- pressure exerted against the
cell wall when the plant is full of water.
Aquaporins- protein channels for the passage
of water between plant cells.
Tonoplast- membrane surrounding the large
central vacuole.
Epiphytes- plants that grow on other plants
(not parasitic).
More terms
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Monoecious- having male and female
reproductive structures on the same
plant. This may occur in some animals.
Dioecious- having separate organisms
for each sex (male and female).
Microsporocytes or microsporangiamale cells
Megasporocyte or megasporangiafemale cells.