1. Plant Reproduction

2. Angiosperms Angiosperms: flowering plants Unique Features Flowers
Fruits
Double fertilization
(by 2 sperm)

3. Cycles differ only in which phases become diploid.
Angiosperm Life Cycle
Alternation of generations:
life cycle regularly alternates between a haploid phase and diploid phase
- Sporophytes: (2n) produces haploid spores by meiosis
- Spore: haploid reproductive cell (gametophyte)
- Gametophyte: haploid phase gametes give rise to diploid phase by mitosis
Cycles differ only in which phases become diploid.

4. Parts of the Flower Male Stamens- male reproductive organs
stamens have stalks (filament) & terminal anthers which carry pollen sacs
pollen sacs produce pollen
pollen grain- gametophyte
sperm-producing structure
Female
Carpels- female reproductive organs
ovary at the base
slender neck - style
within the ovary are 1 or more ovules
within ovules are embryo sacs
female gametophyte - embryo sac
egg-producing structure

5. Plant Reproduction Types
Asexual (vegetative reproduction)
runners, bulbs, grafts, cuttings, vegetative (grass), fragmentation, test-tube cloning
clones
simpler (no pollinator needed)
suited for stable environments
tubers
bulbs
runners
grafting

6. Plant Reproduction Types
Sexual
flower  seeds
genetic diversity
more complex and hazardous for seedlings
advantage in unstable environments

7. Pollination Transfer of pollen from anther to stigma
Self pollination
Cross Pollination
Maximizes genetic variation

8. Mechanisms Prevent Self Pollination
Stamens & carpels may mature at different times
Arranged so that animal pollinator won’t transfer pollen from anthers to stigma of same flower
Self-incompatibility: plant rejects own pollen or closely related plant

9. Fertilization Double fertilization 2 sperm from pollen
1 sperm fertilizes egg diploid zygote
1 sperm fuses with polar nuclei to form n endosperm
endosperm - food tissue in seed
- coconut milk
- grains

10. Development of the Sporophyte (plant embryo)

11. Seeds and Plant Embryo Seed offers: protection for embryo
stored nutrients for growth
of embryo
coytledons- “seed leaves”
- first leaves of new
plant

12. Seeds Mature seed (dormant) Low metabolic rate Growth & development
suspended
Resumes growth when
environmental conditions
suitable for germination

13. Seed Dispersal
Plants produce enormous numbers of seeds to compensate for low survival rate
Vast amount of genetic variation for natural selection to screen
Co- evolution: flowers and pollinators
r-strategy K-strategy

14. Seed Germination Seeds take up water (imbibition)
triggers metabolic changes to begin growth
root develops  shoot emerges  leaves expand & turn green (photosynthesis)
Very hazardous time for plants
vulnerability to predators, parasites, wind

15. Seed Development into a Plant

16. Fruit
Fruit is a mature ovary seeds develop from ovules wall of ovary thickens to form fruit fruits protect dormant seeds & aid in their dispersal