1. Plant Reproduction

2. Is a seed alive? Is a fruit alive?W O R K T G E H
Is a seed alive? Is a fruit alive?

3. Plant reproduction Can be sexual and a sexual
Differs on types of plants

4. Asexual Reproduction
Asexual reproduction is natural “cloning.” Parts of the plant, such as leaves or stems, produce roots and become an independent plant.
List some benefits and some drawbacks to asexual reproduction.
Fast, no mate required.
Beneficial for plants that must compete for scarce resources.
However, all individuals are genetically identical.

5. Sexual Reproduction
Sexual reproduction requires fusion of male cells in the pollen grain with female cells in the ovule.
List some advantages and drawbacks to sexual reproduction.
Fusion of egg and sperm cells.
May be limited to a certain season.
Slower than asexual reproduction.
Allows genetic mixing, increasing variability in a population.

6. Plant Life Cycle

7. Gymnosperms (Non-flowering plants)
Mosses, ferns, and related plants have motile, swimming sperm.
No pollen – spores instead
What kind of environmental conditions would be required for reproduction in these plants?
What kinds of limits does external reproduction impose on these plants?
Reproduction in these plants requires wet conditions, and requires having male and female parts close together.
Living conditions, plant size, and genetic mixing is limited.

8. Moss Life Cycle

9. Fern Life Cycle

10. Conifers also non-flowering plants
Male gamete is contained in a dry pollen grain.
Female gamete is a few cells inside of the structures that become the seed.

11. Conifer life cycle

12. Conifer pollination Conifers are wind-pollinated plants.
Chance allows some pollen to land on the scales of female cones.
Pollen germinates, grows a pollen tube into the egg to allow sperm to fertilize the egg.
What are some advantages and disadvantages to wind pollination?

13. Flowers

14. Pollen go-betweens
Showy flowers are the result of selection for more efficient pollination strategies.
Flower parts are modified leaves. Those that were brightly colored attracted insects in search of pollen.
Why would insects search for pollen? What other rewards do flowers offer?
What are advantages and disadvantages to relying on insects as pollinators?
Pollen itself is a protein-rich food for insects. Some plants offer other rewards, such as nectar.

15. Angiosperms (flowering plants)
Plants that protect their seeds within the body of a fruit.
Make up ¾’s of all plants, including:
Trees, shrubs, herbs,
grasses, water plants…

16. Flower Parts

17. Male Reproductive Structure
The stamen consists of two parts: Anther and Filament
The anther is where meiosis occurs to produce haploid pollen
The filament is a stalk that supports the anther

18. Female Reproductive Structure
The pistil consists of the stigma, style and ovary
The sticky stigma receives the pollen from the anther
The pollen grows a tube down through the style
Meiosis occurs in the ovary to produce haploid ovules (like eggs)

19. Flowers Many different types of flowers
Some have both male and female reproductive organs

21. Reproductive Structures
Sepals: surround and protect the flower bud.
Reproductive Structures
Petals: colourful
structures that attract pollinators.

22. Pollination
Wind, insects or other animals transfer pollen from the anther of one flower to the stigma of another
Flowers vary depending on pollination mechanism

23. Strategy of animal pollination: Attractant & Reward
Nectar
Pollen
Waxes
Resins
or “Trick” instead of a “Treat”
Insect trapped or drowned
Mimicry
E.g., fooling male insect into “mating” with orchid

24. The tricks of flowers
_the_beautiful_tricks_of_flowers

25. Pollination Mechanisms
INSECT
Bees:
fls. showy, colorful, fragrant, with:
nectar guides
landing platforms
Butterflies:
fls showy, colorful, fragrant
no nectar guides
long tubes or spurs

26. Pollination Mechanisms
Moths:
large, white, fragrant
no nectar guides
usually tubes or spurs

27. Pollination Mechanisms
Flies
maroon / brown in color
foul smelling (like rotting flesh)
Pollination Mechanisms

28. Pollination Mechanisms
Birds:
red (often, not always)
tubular (often)
Pollination Mechanisms

29. Pollination Mechanisms
Bats:
nocturnal
large, colorful or white
produce copious nectar or pollen
Pollination Mechanisms

30. Pollination Mechanisms
Wind:
flowers small, numerous, often unisexual
flowers often produced in mass
Pollination Mechanisms

31. Pollination Mechanisms
Water:
Pollination Mechanisms

32. Flowers to Fruit
Once a flower is fertilized, hormones are released from the ovule/ovary
Ovule develops into a seed
Ovary becomes the fruit

33. Flower to Fruit
What is the purpose of fruit?

34. Ovule to Seed

35. Seed Anatomy

36. Seed Germination

37. W O R K T G E H
Use what you have learned about plant life cycles to explain why most mosses and ferns live in moist environments, but flowering plants can live just about anywhere.