1. Ch. 38 Warm-Up Compare and contrast:
What does each of the following develop into?
Zygote
Integument
Ovule
Ovary
Pollination
Fertilization
Germination

2. Angiosperm Reproduction
Chapter 38
Angiosperm Reproduction

3. What you need to know:
The process of double fertilization, a unique feature of angiosperms.
The relationship between seed and fruit.
The structure and function of all parts of the flower.

4. Angiosperms have 3 unique Features:
Flowers
Fruits
double Fertilization

5. Alternation of Generations
Sporophyte (mature plant) produces spores
Spores develop into male (♂) gametophyte (pollen) and female (♀) gametophyte (embryo sac)

8. Flower Structure Reproductive shoots of angiosperm sporophyte
Flower organs:
Sepal – leaflike, protect flower bud
Petal – modified leaves, attract pollinators
Stamen – ♂ reproductive organ
anther + filament
Carpel – ♀ reproductive organ
stigma + style + ovary
Flower attached to stem at receptacle
Pollination by wind, insects, birds

9. Name Structure Function Sepals
Little green leaflets attached to receptacle
Protect the buds
Petals
Brightly colored, 2nd whorl
Attract insects & other pollinators
Stamen
Anther + filament
♂ Reproductive organ
Filament
Thin stalk
Support anther
Anther
Terminal end of filament
Contains chambers to develop male gametophyte (pollen)
Carpel
Stigma + style + ovary
♀ Reproductive organ
Stigma
Sticky end of style
“landing platform” for pollen
Style
Slender neck supporting stigma, leads to ovary
Support stigma and pollen tubes
Ovaries
Swollen lower portion of carpel
Development of ovules

10. Floral Variations Complete: has petals, sepals, stamen, carpels
Incomplete: lacks 1+ of the above
Perfect: has both stamen + carpel
Imperfect: has stamen or carpel, not both (grass - no petals)
Monoecious: plant species w/ both staminate and carpellate flowers on the same individual (corn)
Dioecious: plant species w/ staminate flowers and carpellate flowers on different individual plants (date palm, arrowhead)

11. SYMMETRY
OVARY LOCATION
FLORAL DISTRIBUTION
Bilateral symmetry
(orchid)
Lupine inflorescence
Superior
ovary
Radial symmetry
(daffodil)
Sunflower
inflorescence
Semi-inferior
ovary
Inferior
ovary
Sepal
Fused petals

12. REPRODUCTIVE VARIATIONS
Maize, a monoecious species
Dioecious Sagittaria latifolia (common
arrowhead)

14. Male Gametophyte Female Gametophyte
= Pollen Sac
= Embryo Sac
Produced in anther
Produced in ovule (in ovary)
Has 2 haploid nuclei:
Tube nucleus (forms pollen tube)
Generative nucleus (divides to form 2 sperm cells)
Has 3 important haploid nuclei:
Egg (fuses with sperm)
2 polar nuclei (fuses with 2nd sperm to make 3n endosperm)

15. Pollination: transfer pollen from anther to stigma
Pollen tube grows down into ovary

16. Double Fertilization
Union of 2 sperm cells with different cells of embryo sac
One sperm + egg  zygote (2n)
One sperm + 2 polar bodies  endosperm (triploid 3n)
Endosperm = nutrition for embryo plant
Ovule develops into seed; ovary develops into fruit
Seed = embryo + endosperm

17. “Pin” and “thrum” flower types reduce self-fertilization
Self-incompatibility: prevent reject own pollen or closely related individual
Stigma
Pin flower
Anther
with
pollen
Thrum flower
“Pin” and “thrum” flower types reduce self-fertilization

18. The development of a eudicot plant embryo

19. Fruit Protects enclosed seed(s)
Aids in dispersal by water, wind, or animals
Simple
Aggregate
Multiple
Single ovary of one flower
Many ovaries of one flower
Many ovaries of many flowers
Cherry
Raspberry
Pineapple

20. Developmental origins of fruit

21. Seeds Adaptations: Dormancy = “resting” Dispersal: variety of methods
Low metabolic rate, not growing or developing
Increases chances of germination in most advantageous time & place
Dispersal: variety of methods
Protection: well protected by fruit

24. Seed Structure

25. Germination Imbibition: uptake of H2O
Seed expands and seed coat ruptures
Trigger metabolic changes to begin growth
Enzymes digest storage materials of endosperm (cotyledons)
Nutrients transferred to growth regions of embryo

26. Germination Radicle  Root Shoot tip emerges above ground
Stimulated by light
Foliage leaves expand & turn green  photosynthesis
Very hazardous for plants due to vulnerability
Predators, parasites, wind

27. Dicot and Monocot Seed Germination

28. Plant Reproduction Sexual Asexual Both ways to reproduce
Flower  seeds
Runners, bulb, root, graft,
vegetative (grass), fragmentation
Genetic diversity
Clone
More complex & hazardous for plant
Simpler & safer for plant
Monoculture - cultivate w/ 1 plant
Reduces competition
Benefits farmers

29. Asexual reproduction in aspen trees

30. Test-tube cloning of carrots
Just a few parenchyma cells from a carrot gave rise to this callus, a mass of undifferentiated cells.
The callus differentiates into an entire plant, with leaves, stems, and roots.