Transcript HCI Plant 2014 TEA

PLANT UNITS
LESSON 1: ANATOMY AND
FUNCTIONS
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The Biosphere Depends on Plants
Photosynthesis: a life-sustaining process

Produce glucose  energy source for
plants and consumers

Plants: base of the food chain in many
ecosystem

Responsible for atmospheric oxygen
Kingdom Plantae
 Plants evolved about 500 million
years ago from simple green algae
that lived in the ocean.
 All plants are autotrophic and some,
like the famous Venus fly-trap, can
also be heterotrophic.
 All plants are eukaryotic and
multicellular.
Recall Diversity unit: What adaptations do these
plants have for life on land?
What adaptations do these plants have for
life on land?
• Vascular tissue to transport fluids against gravity
• Light weight pollen and seeds for dispersal by
wind, water, pollinators
• Protective coating to resist desiccation
• Waxy cuticle and stomata in leaves to minimize
water loss and maximize CO2 intake
• Roots to gain access to water
• Flowers to attract pollinators
• Fruits to protect seeds from dryness and disperse
them to the right locations for germination
Plant Cells
 Contain a nucleus and organelles, and 2 special features:
 Cell wall (made of cellulose, a complex carbohydrate, provides
rigid structural support; difficult to digest)
 Chloroplast (organelle that conducts photosynthesis)
Fungi: more related to plants or
animals? WHY (evidence)?
More related to Animals
Evidence:
•Similar protein sequences
(molecular evidence)
•Chitin in cell wall
•Heterotrophs/saprobes
•Store sugars as glycogen
Unit 1 All
Over Again!
• How can plants
stand up straight
without a
skeleton?
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Basic tissues types in Vascular plants
1. Meristematic tissue: where new cells are produced
2. Dermal tissue: outer covering of the plant
3. Ground tissue: most of the inside of plant
4. Vascular tissue: transports water, minerals, nutrients and
provide support
1. Meristematic Tissues
 meristematic tissue: undifferentiated embryonic plant tissue from
which all other plant tissues develop
2. Dermal Tissue
 Outer covering of plant
 Epidermis: single layer cells that forms a
protective covering over the body on
non-woody (herbaceous) plants and
young woody plants

Periderm: found in older
woody plant

Replace the epidermis to form
cork in woody stems and root
2. Dermal Tissue
Guard cells: paired cells that
surround stoma (plural:
stomata)
stomata are openings in
leaves where gas exchange
takes place
Root hairs:
tiny
extensions of epidermal cells on plant
roots  increase surface area available for
absorption of water and nutrients
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3. Ground Tissue
 Form most of the plant’s internal and external material
 Contains parenchyma, collenchyma and sclerenchyma cells
 Functions: photosynthesis, storage and support
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4. Vascular Tissue
 An internal system of tubes that run
lengthwise throughout the stem,
connecting the roots and the leaves
 Woody flowering plants: vascular
tissue is organized into vascular
bundles that are arranged in
concentric rings
 Non-woody flowering plants:
vascular bundles are scattered
throughout the ground tissue
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4. Vascular Tissue
Xylem:
 Transports water and minerals from
the roots to the leaves
 In gymnosperms: xylem consists of
tracheid cells
 In angiosperms: xylem consists of
tracheids and vessel elements
 Start as living cells, grow to fill the
space required and then die and
become hollow, easily allowing water
to move through “pits”
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4. Vascular Tissue
Phloem
 Transports nutrients to cells for
metabolism or to roots for
storage
 Sieve tube elements: have no
nuclei, have plates at both ends
that are perforated with holes
 Companion cells: adjacent to
sieve tubes, have nucleus and
carry out life functions to
support both cells
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Classifying Plants
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Vascular Plant System
 Plants’ arteries and veins
 a network of specialized cells that allows plants to transport water,
minerals and sugar throughout the plant
Shoot system (above ground):
 Stems: provide structural support and transport materials
 Leaves: photosynthesis
Root system (underground):
 anchors the plant by penetrating the soil
 absorbs water and nutrients
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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
4. System of gas exchange
•
Allow CO2 in and O2 out of leaf
Elephant Ear Plant
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Leaves
 Blade: large surface area for
photosynthesis
 Petiole: where a blade attaches to
a stem

Cuticle: transparent waxy substance secreted by the epidermal
cells  reduce water loss by reducing evaporation

Veins: leaf’s vascular tissue

Vascular tissue runs through the petiole connecting the veins
to the stem’s vascular tissue
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Leaves
mesophyll
Leaves
Veins:
 transports water, nutrients
and food
 Made of xylem and phloem
vascular tissue
palisade
spongy
Mesophyll:
 contain chloroplasts
 Spongy mesophyll: loosely packed parenchyma cells 
spaces for gases to move around
 Palisade mesophyll: : tightly packed parenchyma cells that
contains many chloroplasts  maximum exposure to light
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Root
Functions
1. Take in water and dissolved minerals
that are transported to cells
2. Anchor the plant in soil or other
object, support the plant against wind
and water
3. Store carbohydrates, water and
nutrients
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Root
Hairs
Root
1.Root Hairs: increase
surface area for water &
mineral absorption
2.Meristem: region where
new cells are produced
Meristem
Root
Cap
3.Root Cap: protects tip of
growing root
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Types of Root
1. Taproot
 A thick root with smaller lateral branching roots
 Functions: anchor plants, absorb water and minerals, food and
water storage
2. Fibrous root
 Made up of many smaller branching roots
 Roots are about the same size and grow from a central point
 Do not grow as deep as taproot
 Functions: anchor plant, absorb water and mineral
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Stem
Functions
1. Support system for plant body
2. Transport system carries water & nutrients (through vascular
tissue!)
3. Holds leaves & branches upright
 Can be woody or herbaceous
 Annual: plants that live for only 1 growing season
 Perennials: plants that live for more than 2 growing season
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Stem
Bark:
 layers of tissue from the xylem outward in woody plants
 seasonal variations in moisture and other factors create annual
growth rings  age of tree
What years had
the most rain?
What years
experienced the
worst drought?
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Types of Stem
Tuber
 Enlarged part of an underground stem
 Has buds that will into new plants e.g. potatoes
Bulbs
 Shortened, compressed stems surrounded by
fleshy leaves e.g. tulips and onions
Corms
 Stem tissue with some scaly leaves at its top
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Types of Stem
Stolons
 Horizontal stems that grow above
ground along with the surface of
the soils
 e.g. strawberry plants
Rhizomes
 Horizontal stems that grown
underground
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Monocots and Dicots
Monocot
Non-woody plants
One
cotyledon
Dicot
Woody plants
Two
cotyledon
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