Kingdom Plantae Introduction

Characteristics  There are more than 280,000 plant species on Earth  Photosynthetic  Cell walls made of cellulose  Stems and leaves are coated with a waxy cuticle that prevents dessication (drying out)  Oxygen and carbon dioxide are exchanged between plants and their environment and gas exchange occurs through tiny openings in the leaf called stomata

Stomates and Guard Cells

What evidence is there that plants evolved from green algae (Chlorophytes)? Homologous chloroplasts with chl a, chl b and caretonoids Biochemical similarities such as cellulose as and caretonoids Biochemical similarities such as cellulose as the cell wall structure Food stored as starch Similar cell plate formation Similar sperm structure Similar genes and rRNA’s the cell wall structure Food stored as starch Similar cell plate formation Similar sperm structure Similar genes and rRNA’s

Advantages to Land  Lots of room  Lots of light and gases  Soil rich in nutrients  Originally no herbivores on land

5 Characteristics of All Plants 1. All plants have an apical meristem. This is the tip of the root and the shoot. All cell division occurs here. 2. All plants have cuticles, stomata, and mechanisms to move water throughout their bodies.

5 Characteristics of all Plants All plants undergo alternation of generations 3.All plants have a sporophyte (2n) generation with cells that undergo meiosis to produce haploid spores (n). 4.These spores grow into multicellular gametophytes which produce gametes (n). The male gametophyte is called the antheridium, while the female gametophyte is called the archegonium. 5.The male and female gametes fuse to form the sporophyte (2n).

Alternation of Generations

Moss generations…

Sporophyte close up…

Male gametophytes (antheridia with sperm “gametes”)

Close up of antheridium with sperm.

Archegonium with egg (gamete)…

Fertilization…