Transcript Kingdom Plantae Introduction

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
the cell wall structure
Food stored as starch
Similar cell plate formation
Similar sperm structure
Similar genes and rRNA’s
Advantages to Land
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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…
Moss generations…
Sporophyte close up…
Male gametophytes
(antheridia with sperm
“gametes”)
Close up of antheridium
with sperm.
Archegonium with egg
(gamete)…
Fertilization…