1. Slide 1
Structure of
Plants

2. A. Functions of Roots Anchor & support plant in the ground
Slide 2
A. Functions of Roots
Anchor & support plant in the ground
Absorb water & minerals
Hold soil in place
Fibrous Roots
Root Hairs

3. B. Root Types
Slide 3
Tap Root
1. Fibrous Roots: branching roots hold soil in place to prevent soil erosion
Ex. Grasses
2. Tap Roots –larger central root reaches deep water sources underground
Ex. Trees, Carrots, & Dandelions

4. C. The Structure of a Root
Slide 4
Root Hairs
Root Hairs: increase surface area for water & mineral absorption
Meristem: region where new cells are produced
Root Cap: protects tip of growing root
Phloem
Xylem
Meristem
Root Cap

5. A. Functions of Stems Support system for plant body
Slide 5
Support system for plant body
Transport system carries water & nutrients
Holds leaves & branches upright
Looking at the picture to the left:
What years had the most rain?
What years experienced the worst drought?
Each light and dark tree ring equals one year of annual growth. Light rings for fast spring growth, dark for slow summer growth.
Smaller rings tell of past droughts that have occurred.

6. A. Functions of Leaves Main photosynthetic organ
Slide # 6
Main photosynthetic organ
Broad, flat surface increases surface area for light absorption
Have systems to prevent water loss
Stomata open in day but close at night or when hot to conserve water
waxy cuticle on surface
System of gas exchange
Allow CO2 in and O2 out of leaf
Elephant Ear Plant

7. B. Leaf Structures Leaf Cross-Section
Slide # 7
Leaf Cross-Section
Cuticle: waxy layer; covers upper surface
Protects leaf against water loss
Veins: transports water, nutrients and food
Made of xylem and phloem
Mesophyll: contains cells that perform photosynthesis
b/c they contain Chloroplasts.
Cuticle
Veins
Mesophyll
Stoma
(Opening)
2 Guard Cells
Surround
each
Stoma
Stoma- singular
Stomata-plural

8. cells that open and close the stoma
More Plant Parts…
Slide # 8
Guard cells:
cells that open and close the stoma
Stomata: openings in leaf’s surface; when open:
GAS EXCHANGE: Allows CO2 in & O2 out of leaf
TRANSPIRATION: Allows excess H2O out of leaf
Guard Cells
Stoma

9. Function of Stomata
Slide # 9
What process involves using CO2 and H2O releasing O2 as a waste product?
Photosynthesis
What is the plant using this process to make?
Carbohydrates-glucose
If the plant needs water for photosynthesis, why is water coming out of the stoma?
Guard Cells
Guard Cells
What goes out? O2
H2O
CO2
What goes in?
Stoma Open
Stoma Closed
Stoma

10. Function of Guard Cells
Slide # 10
These stomata (leaf openings) naturally allow water to evaporate out.
Why would the plant close stomata with guard cells?
Prevent excess water loss through transpiration. (conserve water)
So what is the point of having stomata?
Allow gas exchange for photosynthesis
Guard Cells
Guard Cells
Stoma Open
Stoma Closed
Guard cells open by inflating with extra water. They do this by pumping K+ ions into the cell, which causes water to rush in via osmosis to diffuse the high ion concentration.

11. C. Plants find a use for Transpiration
Slide # 11
Transpiration: loss
of excess water from plant leaves
2. Significance:
Transpiration causes enough pressure to help pull water (& required nutrients) up stem from roots.
As part of the water cycle, trees transpire water back into the atmosphere.
Transpiration provides much of the daily rain in rainforest. A B
A average size maple tree can transpire 200 liters of water per hour during the summer.
Transpiration is the #1 driving force for pulling water up stems from roots.

12. Structure of a Flower 1.Pistil:female reproductive structure
Slide # 12
Filament
Anther
Stigma
Style
Ovary
Pistil
Petal
Sepal
Ovule
Stamen
1.Pistil:female reproductive structure
Stigma: sticky tip; traps pollen
Style: slender tube; transports pollen from stigma to ovary
Ovary: contains ovules; ovary develops into fruit
Ovule: contains egg cell which develops into a seed when fertilized

13. Structure of a Flower Stamen: male reproductive structure
Slide # 13
Filament
Anther
Stigma
Style
Ovary
Pistil
Petal
Sepal
Ovule
Stamen
Stamen: male reproductive structure
Filament: thin stalk; supports anther
Anther: knob-like structure; produces pollen
Pollen: contains microscopic cells that become sperm cells

14.  Structure of a Flower
Slide # 14
Filament
Anther
Stigma
Style
Ovary
Pistil
Petal
Sepal
Ovule
Stamen
Sepals: encloses & protects flower before it blooms
Petals: usually colorful & scented; attracts pollinators

15. Cross Pollination How does pollination happen?
Slide # 15
Cross Pollination
How does pollination happen?
Pollen from an anther is caught by the stigma, travels through style to the ovules in the ovary.
What is the result of pollination?
A Fruit: An ovary containing seeds.

16. Plant Responses and Adaptations
Slide # 16
Chapter 25
Plant
Responses
and
Adaptations

17. Hormone Action on Plants
Hormone-producing
cells
Hormone Action on Plants
Slide #17
A. Plant cells can produce hormones: which are chemical messengers that travel throughout the plant causing other cells called target cells to respond.
B. In plants, hormones control:
Plant growth & development
Plant responses to environment
Movement
of hormone
Target
cells
Cells in one blooming flower signals other blooms using hormones to open.

18. C. Plant cells will send signals to one another to tell them:
Slide # 18
C. Plant cells will send signals to one another to tell them:
When trees to drop their leaves.
When to start new growth.
When to cause fruit to ripen.
When to cause flowers to bloom.
When to cause seeds to sprout.
Leaf Drop
Tree Budding
Fruit
Ripening
Cactus
Blooming
Sprouting
Corn Seeds

19. D. Ethylene causes Fruit to Ripen
Slide # 19
D. Ethylene causes Fruit to Ripen
Fruit tissues release a small amount of ethlyene
Causes fruits to ripen.
As fruit become ripe, they produce more and more ethlyene, accelerating the ripening process.
Ethylene released by apples and tomatoes causes fruit to age quickly.

20. Slide # 20
Plant Tropisms
1. Tropism: the way a plant grows in response to stimuli in the environment.
Phototropism: growth response to light
-Plants bend towards light
Geotrophism: growth response to gravity
-plant roots grow down with gravity, shoots (stems) grow up against gravity and out of the soil.
Thigmotropism: growth response to touch
-vines grow up around trees, venus flytrap closes when leaves are touched

21. Thigmotrophism Phototropism Thigmotrophism
Slide # 21
What type of tropism is shown in these pictures?
Phototropism
Geotropism
Thigmotrophism
Phototropism
Geotropism
Thigmotrophism

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