Angiosperm Reproduction in the Plant .ppt

Learn about the angiosperm in plant reproduction

1. Angiosperm Reproduction
She loves me, or she loves me
not

2. I. Terminology
•A.homosporous
•B.heterosporous
•C.meiosis produces spores in sporangia
•D.heterosporous plants
–Megasporangia produce megaspores
–Microsporangia produce microspores

3. II.Flower structure
•A.modified branch
•B.receptacle
•C.sepals (calyx)
•D.petals (corolla)
•E.stamen
(andromecium)
•F.(carpels) pistil

4. •G. stamen
(andromecium)
–1. anther
–2. microsporangia
–3. meiosis of microspore
mother cells produce pollen

5. •H. Pistil
–1. stigma
–2. style
–3. ovary

6. Stigma

7. I.Ovary
•1. ovules
•2. megasporangia
•3. megaspore mother
cells
•4. site of meiosis
•5. produces
megaspores-first cell of
gametophyte generation

8. I. Ovule (megasporangium)
•1.many located inside
ovary
•2.megasporangium
•3.contains megaspore
mother cell
•4. site of meiosis

9. III.Pollination Biology
•A.Symbiosis
• 1.definition
2. example

10. B. Pollinator/flowers found in symbiotic
relationships
• 1. pollinators and flowers have co-evolved to
bring about specializations
• 2. insures that flowers are visited by one type
of pollinator-what advantage is garnered by the
flower
• 3. pollinator gets a monopoly on a food source-
no competition with other species

11. C.Bees and their flowers
• 1. Biology of a honeybee
• a. land to feed
• b. short tongues
• c. good sense of smell
• d. active during day
• e. see yellows/violets

12. 2. Flower adapted to bee
• a. Petals open flat
• b. Short corolla tube
• c. Lightly aromatic
• d. Open during day
• e. yellow

13. Bee pollinated flowers

14. Beetle pollinated flowers

15. D. Hummingbirds and their flowers
•1. Hummingbird traits
• a. hover to feed
• b. long tongues
• c. poor sense of smell
• d. active during day
• e. see reds
• 2. Flower’s traits

16. E. Wind pollinated flowers
•How is this flower
different than others seen
before?
•What is the significance
of this difference

17. IV.Gamete production
•A.Meiosis produces spores in sporangia
•B.Angiosperms are heterosporous
• 1. megaspores are produced in
megasporangia by meiosis (ovules)
• 2. microspores are produced in
microsporangia by meiosis (anthers)

18. C.Events in the ovule
• 1.Structure of ovule
• 2. Meiotic division of megaspore mother cell
• 3. Mitotic division of megaspore to produce
embryo sac-female gametophyte tissue

19. D.Events in the anther
•1.Structure of the anther
• 2. Meiotic division of the microspore mother cell
• 3. Mitotic division of the microspores to form
pollen grains.

20. E.Events of pollination
• 1. Pollen lands on
stigma
• 2. Pollen tube begins
to grow
• 3. Part way down the
style the generative
nucleus divides to form
two sperm cells
• 4. Products delivered
to the micropyle

21. Pollen tubes start to grow down style

22. Pollen tubes

29. F.Fertilization
• 1.double fertilization
• 2. one sperm fertilizes
the egg to form the
zygote
• 3. second sperm
fertilizes the egg to form
the triploid endosperm
tissue
• 4. endosperm is a
nutritive tissue equivalent
to the yolk in a bird egg

30. Double fertilization

31. Double fertilization

32. G.Seed development
• 1.zygote becomes
embryo
• 2. integuments of ovule
become seed coat-
impermeable to water
• 3. triploid endosperm food
source
• 4. seed dessicates to
approximately 5-10% water-
enters a period of dormancy
• 5. state of hibernation
• 6. ovary wall develops into
fruit

33. H.Functions of fruits
• 1. examples of fruits
• 2. fall into different categories
• 3. dispersal of seed from parent
• 4. does not function to provide food for the
germinating seed

34. G.Germination
• 1. breaking of dormancy
• a. Period of cold
weather
• b. Sustained rain
• c. Fire in prairie
• 2. imbibtion of water with
breakdown of seed coat
• 3. emergence of radicle
• 4. breaking of soil by
shoot
• 5. feels like just given birth

35. Germination of a monocot