1. Sexual Reproduction in Plants
Slide 1
Sexual Reproduction in
Plants

2. Stigma Ovary  Fruit Anther Style Ovule  Seed Filament Ovule Petal
Slide # 2
Flower Structure
Stigma
Ovary  Fruit
Anther
Style
Ovule  Seed
Filament
Ovule
Petal
Sepal
Pistil (female Part)
Stigma
Style
Ovary
Stamen (Male Part)
Anther
Filament
Receptacle
Ovary

3. Structure of a Flower 1.Pistil:female reproductive structure
Slide # 3
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

4. Structure of a Flower Stamen: male reproductive structure
Slide # 4
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

5. Slide # 5

6. Perfect & Imperfect Flowers
Slide # 6
Perfect Flower ~ has pistil & stamen
Imperfect Flower ~ only one sex
Which is male? Female?

7.  Structure of a Flower
Slide # 7
Filament
Anther
Stigma
Style
Ovary
Pistil
Petal
Sepal
Ovule
Stamen
Sepals: encloses & protects flower before it blooms
Petals: usually colorful & scented; attracts pollinators

8. What are the functions of each part?
Slide # 8
What are the functions of each part?

9. Pollination
Slide # 9
The transfer of pollen grains from the anther to the stigma.
Pollination may be aided by wind, insects, and birds. In some instances, the colored petals act as a visual attractant for insects.
If pollination occurred in a dry environment, the pollen would not dehydrate (dry up) due to a thick wall that surrounds it.
Two types of pollination:
1. Self-Pollination
2. Cross-Pollination

10. Allows for variations due to the combination of two different plants.
Self-Pollination
Slide # 10
The transfer of pollen grains from the anther to the stigma of the same plant.
Cross-Pollination
The transfer of pollen grains from the anther of a flower on one plant to the stigma of a flower on a different plant.
Allows for variations due to the combination of two different plants.

11. Pollen tube is an adaptation for internal fertilization.
Slide # 11
Following pollination, the pollen grain germinates to the stigma and forms a pollen tube.
Pollen tube is an adaptation for internal fertilization.
2 Haploid sperm cells travel down the pollen tube and only one fertilizes the egg in the ovule.

12. Fertilization and Embryo Development
Slide # 12
The union of a sperm cell and an egg cell results in the formation of a zygote
The zygote undergoes development resulting in the formation of an embryo (ripened ovule)
The ripened ovule (embryo) develops into the seed
The ripened ovary develops into the fruit

13. Structure of a Seed (embryo)
Slide # 13
Structure of a Seed (embryo)
Hypocotyl: Develops into
roots and in some
species lower stem.
Radical: Develops in roots
Epicotyl: Develops into
leaves and upper stem
Cotyledon: Stored food for
early development of embryo
(seed leaves)

14. Slide # 14
Structure of a Seed
Epicotyl

15. forms from outer layer of ovule protects embryo
Slide # 15
Seed coat:
forms from outer layer of ovule
protects embryo
Endosperm: food storage tissue
(the other sperm creates this triploid (3n) structure
when it fertilizes 2 polar bodies from oogenesis)

16. Monocots – seeds with one cotyledon (corn)
Slide # 16
Monocots & Dicots
Monocots – seeds with one cotyledon (corn)
Dicots – seeds with two cotyledons (bean, peanut)

17. Germination and Growth
Slide # 17
Germination and Growth
Fruits are specialized structures which aid in seed dispersal. Seeds develop inside the fruit. If the temperature and moisture levels are sufficient, the dispersed seeds will germinate (activate and grow).
Growth in most plants occurs in the meristems.
The organs of a plant are developed in the meristems.
Apical Meristems are found in the tips of roots and stems and cause the plant to grow in height.
Lateral Meristems are between the xylem and phloem and cause the plant to grow in diameter (get wider).

18. Plant Responses and Adaptations
Slide # 18
Plant
Responses
and
Adaptations

19. Hormone Action on Plants
Hormone-producing
cells
Hormone Action on Plants
Slide #19
A. Plant cells can produce hormones (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.

20. High Auxin ~ stimulates stem growth ~ inhibits root growth
Plant Hormones
Slide # 20
Auxin
High Auxin ~ stimulates stem growth
~ inhibits root growth
Low Auxin ~ reverse effect
Gibberellin
Increases stem growth
Increases fruit and seed development

21. Plant cells will send signals to one another to tell them:
Slide # 21
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

22. Ethylene causes Fruit to Ripen
Slide # 22
Ethylene causes Fruit to Ripen
Fruit tissues release a small amount of ethlyene
Ethylene is a gaseous hormone
Causes fruits to ripen
As fruit become ripe, they produce more and more ethlyene, accelerating the ripening process
Fruit picked before ripened….spray w/ethylene at destination to ripen
Ethylene released by apples and tomatoes causes fruit to age quickly.
What type of feedback?

23. Slide # 23
Plant Tropisms
Tropism: the way a plant grows in response to stimuli in the environment caused by an unequal distribution of auxin.
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

24. Thigmotrophism Phototropism Thigmotrophism
Slide # 24
What type of tropism is shown in these pictures?
Phototropism
Geotropism
Thigmotrophism
Phototropism
Geotropism
Thigmotrophism