Your SlideShare is downloading. ×
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Angeosperms
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Angeosperms

1,351

Published on

Published in: Technology, Business
0 Comments
2 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total Views
1,351
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
60
Comments
0
Likes
2
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. ANGEOSPERMS                                                                                    
  • 2. GENERAL CHARACTERISTICS
    • Enclose their seed in masses of tissue = fruit
      • Fruit protects and aids in the distribution of seeds
    • Their xylem is more specialized and transports water and minerals more efficiently
    • Found in nearly every habitat
  • 3. Why Sucessful
    • Have evolved mechanisms for dispersal of both pollen and seeds
      • Pollen Dispersal – co-evolution of flowers that provide nectar which increases the probability of successful pollination
      • Seed Dispersal- co-evolution for fruits covering seeds which increases distance of seed dispersal from the parent plant
  • 4. THE TWO SUBCLASSES
    • MONOCOTS AND DICOTS
    • MONOCOTS include corn, wheat, lilies, daffodils, orchids, and palms
    • DICOTS include roses, clover, tomatoes, oaks, and daisies
    • There are several differences between these two groups:
  • 5. Name of organ Monocots Dicots Coteledons = leaves of embryo One seed leaf Two seed leaves Stem thickness Don’t grow thicker yearly Grow thicker yearly
  • 6. Name of plant organ Structure in monocots Structure in dicots Function of organ ROOTS One function of a root is to absorb water and nutrients. A second function is to anchor the plant to keep it from moving.  
  • 7. STEMS One function is to provide support A second is to transport water to leaves and sugars to root
  • 8. Name of plant organ Structure in monocots Structure in dicots Function of organ LEAVES One function is to capture sunlight A second is to provide the function of photosynthesis in special organelles A third is to provide exchange for CO 2 and O 2 (carbon dioxide in and oxygen out)
  • 9. Name of plant organ Structure in monocots Structure in dicots Function of organ FLOWERS AND FRUITS Sexual reproduction
  • 10. Sexual Reproduction in Angiosperms                                          
  • 11. Most are terrestrial and all lack locomotion. This poses several problems.
    • Gametes are delicate single cells. For two plants to cross fertilize, there must be a mechanism for the two gametes to reach each other safely.
    • There must also be a mechanism to disperse their offspring far enough away from the parent so that they do not have to compete with the parent for light, water, and soil minerals.
    • The functions of the flower solve both of these problems.
  • 12. The Flower and Its Pollination
    • In angiosperms, meiosis in the sporophyte generation produces two kinds of spores.
    • microspores
      • which develop in the microsporangium and
      • which will germinate and develop into the male gametophyte generation and
    • megaspores
      • which develop in the megasporangium and
      • which will develop into the female gametophyte generation .
  • 13. TYPES
    • Both types of sporangia are formed in flowers.
    • In most angiosperms, the flowers are perfect : each has both microsporangia and megasporangia.
    • Some angiosperms are imperfect , having either microsporangia or megasporangia but not both.
      • Monoecious plants have both types of imperfect flower on the same plant.
      • Dioecious plants have imperfect flowers on separate plants; that is, some plants are male, some female. Examples include willows, poplars, and the date palm.
  • 14. Parts of the Flower
      • stamens in which the microsporangia form
      • carpels in which the megasporangia form.
  • 15. Stamens
    • Each stamen consists of a
    • lobed anther , containing the microsporangia and supported by a thin filament
    • Meiosis of the diploid microspore mother cells in the anther produces four haploid microspores . Each of these develops into a two-celled pollen grain .
    • The two cells are the
      • tube cell and the
      • generative cell
  • 16. Carpels
    • Carpels consist of a
    • stigma , usually mounted at the tip of a
    • style with an
    • ovary at the base.
    • Often the entire whorl of carpels is fused into a single pistil .
    • The megasporangia, called ovules , develop within the ovary.
    • Meiosis of the megaspore mother cell in each ovule produces 4 haploid cells:
      • a large megaspore and
      • 3 small cells that disintegrate.
  • 17. Development of the megaspore
    • The nucleus of the megaspore undergoes 3 successive mitotic divisions. The 8 nuclei that result are distributed and partitioned off by cell walls to form the embryo sac . This is the mature female gametophyte generation .
    • The egg cell will start the new sporophyte generation if it is fertilized.
    • The large central cell, which in most angiosperms contains two polar nuclei , will after its fertilization develop into the endosperm of the seed.
  • 18.  
  • 19. Pollination
    • When a pollen grain reaches the stigma, it germinates into a pollen tube . The generative nucleus divides by mitosis forming 2 sperm nuclei . These, along with the tube nucleus, migrate down the pollen tube as it grows through the style and into the ovule chamber.
    • The pollen tube with its contents makes up the mature male gametophyte generation .
  • 20. Double fertilization
    • The pollen tube enters the ovule through the micropyle and ruptures.
    • One sperm nucleus fuses with the egg forming the diploid zygote .
    • The other sperm nucleus fuses with the polar nuclei forming the endosperm nucleus . Most angiosperms have two polar nuclei so the endosperm is triploid (3n).
    • The tube nucleus disintegrates.
  • 21. Self-incompatibility
    • Most angiosperms have mechanisms by which they avoid self-fertilization.
  • 22. Fruits
    • Fruits are a development of the ovary wall and sometimes other flower parts as well.
    • Fruits promote the dispersal of their content of seeds in a variety of ways.
      • Wind. The maple "key" and dandelion parachute are examples.
      • Water. Many aquatic angiosperms and shore dwellers (e.g., the coconut palm) have floating fruits that are carried by water currents to new locations.
      • Hitchhikers. The cocklebur and sticktights achieve dispersal of their seeds by sticking to the coat (or clothing) of a passing animal.
      • Edible fruits. Nuts and berries entice animals to eat them. Buried and forgotten (nuts) or passing through their g.i. tract unharmed (berries), the seeds may end up some distance away from the parent plant.
      • Mechanical. Some fruits, as they dry, open explosively expelling their seeds. The pods of many legumes (e.g., wisteria) do this.
  • 23.  
  • 24.  

×