Transcript Parts of a Vascular Plant

PLANTS
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Parts
Clasification
Reproduction
Parts of a Vascular Plant
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vertical axis
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Underground: root to
absorb water and ions
and anchor
above ground: shoot:
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stem serves as a
framework for
positioning the leaves
Leaves: photosynthesis
takes place
growth zones:
unspecialized cells
called meristems
Tissue Types
1.
Dermal:
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2.
outer protective covering
covered by a waxy layer called the cuticle, effective
barrier against water loss
Vascular: 2 types
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Xylem
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water and minerals pass from the roots to the shoots, when
water reaches the leaves, most exits through the stomata
Phloem
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principal food-conducting tissue
1. Roots
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Main Roots have:
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central column of xylem
alternating are strands of phloem
surrounding the central column, a cylinder of cells
called pericycle: branch or lateral roots form from
A root cross section
2. Stems
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Growth:
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Primary: leaves appear while the
apical meristem elongates
Secondary: differentiation of the
vascular tissue
vascular tissue types:
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dicots, vascular bundles (xylem
and phloem) are around the
outside of the stem
monocots, vascular bundles are
scattered throughout
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places of the stem where
leaves form are called
nodes
portions of the stem
between these leaf
attachment points are
called internodes
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source of economically
important product: wood
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is accumulated xylem
displays rings based on the
growth rate differences:
cambium divides more
actively in the spring and
summer
bark (periderm): all of the
tissues of a mature stem
outside of the vascular
cambium including the cork
3. Leaves
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Growth: marginal
meristems which grow
outward and ultimately form
the blade (the flattened
portion) of the leaf
leaf veins, comprised of
xylem and phloem, run
through the leaf
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dicots, the veins have a net or
reticulate venation
monocots, the veins are
parallel
Water Movement
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factors:
1.
initial movement of water into the roots: osmosis
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2.
3.
fluid in the xylem contains more solutes than the surroundings
capillary action adds “pull” to the movement of water up
A final “pull” is transpiration, water evaporating from the top (leaf) of
the tube pulls the column of water up
4.
the column of water does not collapse because water molecules are
attracted to each other
5.
the narrower the diameter of the tube, the more tensile strength, or
resistance to separation, of the water column
Plant Classification
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complex multicellular organisms
Autotrophs, feed themselves by photosynthesis
almost exclusively on land
dominant organisms on the surface of the earth
Plant Evolution
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ancestor probably: green algae
Four key evolutionary advances:
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alternation of generations,
vascular tissue, transports water and nutrients and
provides support
Seeds, provide nutrients and protection for the plant
embryo until it encounters favorable growing
conditions
flowers and fruits, facilitated fertilization and
dispersal of their seeds
1. Nonvascular Plants
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size limited
materials transported by
osmosis and diffusion
mosses
2. Seedless Vascular Plants
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ferns
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sporophyte generation is
much larger and complex
Vascular Tissue
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specialized cylindrical
or elongated cells that
form a network
throughout a plant
3. Vascular, Seed Plants
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Seed: crucial adaptation to land to protect the
embryonic plant
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produce two kinds of gametophytes:
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develop within the sporophyte
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gymnosperms
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male: pollen grains
female: egg within an ovule
ovules are not completely enclosed
angiosperms
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ovules are completely enclosed
Gymnosperms
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Conifers,
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Cycads,
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seeds in cones
most needle-like leaves
palmlike leaves
Ginkgo,
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fan-shaped leaves
Angiosperms: flowers
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90% all living plants
Embryos store food
reserves in seed leaves
or cotyledons
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monocots have one
cotyledon
dicots have two
cotyledons
Angiosperm Reproduction
1.
2.
sexual
Asexual
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Asexual, vegetative
reproduction
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new individuals are cloned
from parts of the parent
Samples:
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Runners, stems growing
along the soil
Rhizomes, underground
horizontal stems
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Sexual reproduction: alternation of generations
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male gametophytes: pollen grains
female gametophyte: embryo sac
Flowers
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Base: receptacle
four concentric circles:
1. Sepals, protect
2. Petals, attract pollinators
3. male parts: stamens, anther
with the pollen grains
4. female parts: ovules in the
bulging base called ovary, a
stalk style, sticky tip stigma
to receive the pollen
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different kinds of flowers: because insects and
plants coevolved
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insects specialize in visiting particular kinds of flowers
Birds also pollinate some flowers, especially red ones
Formation of pollen and egg
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Eggs develop in the ovules
each ovule contains a megaspore mother cell
that undergoes meiosis to produce four haploid
megaspores, only one survives to undergo
repeated mitotic divisions that produce eight
haploid nuclei
Pollination
 process by which pollen is transferred from the
anther to the stigma
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gymnosperms, pollen is dispersed by wind; species
must grow close, flowers are small, green, and
odorless
angiosperms use animals to carry pollen from flower
to flower and are rewarded with food; e.g., nectar
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Pollen grains adhere to the surface of the
stigma and begin to grow a pollen tube until it
reaches the ovule in the ovary, entry to the
embryo sac
it releases two sperm cells: double
fertilization
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one sperm fertilizes the egg
the other sperm goes on to form endosperm
Seed
three parts
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1.
2.
3.
embryo
endosperm, a source
for food for the
developing embryo
(cotyledons)
a drought-resistant
protective cover
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Seeds improved the adaptation of plants to
living in land:
1.
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3.
Dispersal into new habitats
Dormancy and Germination, plants postpone
development until conditions are favorable
Nourishment; provisions the seed during the
critical period just after germination
Fruits
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Is a mature ripened ovary containing fertilized seeds
angiosperms use fruits to have animals aid in the dispersal of
seeds; although eaten the seeds are resistant to chewing and
digestion passing out with the feces and ready to germinate
Types of fruits and common modes
of dispersion
Practice questions
1. Growth in vascular plants is regulated and coordinated by:
A)
photosynthetic tissue
B)
root tissue
C)
meristematic tissue
2. In vascular plants, phloem tissue transports _______
3. In stems, the tissue responsible for secondary growth is the:
A)
Collenchyma
B)
Pith
C)
Cambium
D)
cortex
4. One difference between monocot/dicot plant stems is the:
A)
absence of buds in monocots
B)
organization of vascular tissue
C)
presence of guard cells
5. Which of the following is not a process that directly assists
in water movement from the roots to the leaves?
A)
photosynthesis
B)
root osmotic pressure
C)
capillary action
D)
transpiration
6. Sexual reproduction in angiosperms requires male _______
7. The flower shape, scent, color, nectar in the flowers of some
angiosperms are related to the plant's __
9. Fruit forms from a flower's:
A)
Ovary
B) sepals
C) carpels
D) stigma
10. Which of the following structures does not give the plants an
evolutionary advantage?
A)chloroplasts
B)vascular tissue
C)seeds
D)flowers
11. Mosses do not reach a large size because -----------12. One characteristic that separates ferns from more complex vascular
plants is that ferns do not have ---------
13. What separates the gymnosperms from the rest of the vascular plants is:
A)
a vascular system
B)
ovules completely covered
C)
ovules not completely covered
D)
fruits and flowers
14. What separates the angiosperms from the rest of the vascular plants is:
A)
a vascular system
B)
ovules completely covered
C)
ovules not completely covered by the sporophyte
D)
fruits and flowers
15. Flower shape and color can be linked to the process of ------------16. If the seeds of a plant are encased in a fleshy fruit, then the most likely form of
dispersal is:
A)
to attach to an animal's fur or skin
B)
Wind
C)
an animal's digestive system and processes
D)
water