AngiospermsNoor HamidehShereen Abbas

Introduction• Angiosperms are plants that

produce flowers and form seeds within an ovary that develops into a fruit.

• Latin for ‘closed seed’• Most common land plants

(~250,000 species)• Reproduce sexually by

pollination

Angiosperm Diversity

Flower Diagram

The Flower• Reproductive structure• Sepals and Petals: Outer part of flower• Stamen: Male reproductive part• Anther: Produces pollen grains

containing sperms• Carpel: Female reproductive part• Ovary: Produces eggs inside ovule,

develops into fruit• Ovule: Houses egg, develops into seed• Stigma: The carpal opening

Life Cycle

Life Cycle• Requires a good, moist environment• Seeds and ovules are well protected

due to the flower structure• The ovum must be fertilized by a

sperm cell contained in a pollen grain

• The fertilized egg develops into an embryo contained in a seed contained in a fruit

• The fruit cannot develop unless the seed is fertilized

1. Pollination• Pollination is the transfer of

pollen from the anther of a stamen to the stigma of a carpal.a) Self pollination: Pollen from

the same plant fertilizes the egg cell of that plant

b) Cross pollination: More common, pollen is transferred from one plant to another (of the same species) by wind, water, or animals.

• Flowers are adapted to one of these methods

2. Fertilization

2. Fertilization1. Pollen grain lands on stigma2. Pollen tube grows down into ovary3. 1 of 2 nuclei in the pollen divides into

2 sperm nuclei4. 1 nucleus fuses with the egg to

produce a fertilized egg5. The other nucleus fuses with the ovule

to become endosperm tissue, that provides nutrition

6. The ovule becomes a seed, and the ovary a fruit.

7. Other flower parts die

2. Fertilization

3. Seed Dispersal• Seed dispersal is the way seeds

find soil in which to germinate(sprout), it includes:

a) Being blown by wind (ex: dandelion)

b) Being carried on waterc) Having hooks that attach to furd) Being eaten by animals and

excreted into soil

The EndNoor HamidehShereen Abbas