Life Cycle

1
Chapter 22.1

• Life Cycle
• And
• History of Plants

2
Plant Life Cycle

• Alternation of Generation
• Between haploid (N) and diploid (2N) phase
• Between Gametophyte (N) and Sporophyte (2N)
  plants
• One phase must be dominant
• The dominant phase changes with the different
  plant phyla

3
Alternation of Generation
Spores (N)
Sporophyte plant (2N)
Gametophyte plant (N)
Sperm (N)
Fertilization
Egg (N)
4
History of Plants

• What is the evolutionary relationship between
• Bryophytes
• Pterophytes
• Gymnosperms
• Angiosperms

5
History of Plants
Plants
Aquatic Green Algae
6
History of Plants
Flowering Plants
Cone-bearers
Ferns
Mosses
Aquatic Green Algae
Flowers Fruit
Seeds
Vascular Tissue
Dry Land
SIMPLE
COMPLEX
7
Modern Plants

• 235,000 species (90)
• 15,600 (5)
• 11,000 (4)
• 760 (1)

• Flowering Plants
• Mosses
• Ferns
• Cone-bearing