Plant Diversity. The Evolution and Classification of Plants. Warm-up: Write each Question and Answer for Each. What do I know about plants? True or False. All plants perform photosynthesis. All plants need water and nutrients. All plants reproduce using flowers.
The Evolution and Classification of Plants
What do I know about plants?
True or False
Plants Make the The Move to Land
The ancestors of plants were multicellular green algae. They were completely immersed in water & dissolved minerals.
To move onto land, plants had to solve these problems:
How to get chemical resources (water, minerals, oxygen, and carbon dioxide) separated into air and soil
How to transport resources within the plant.
How to prevent from drying out
How to reproduce without water
Some Adaptations (solutions)-
Have body parts extending into both air and soil
Develop a vascular system to transport resources in plant
Have a protective layer – cuticle (waxy outer layer) to keep from drying out
Specialized structures for reproduction including spores & seeds that do not dry out
Has NO Vascular Tissue
Has Vascular Tissue
Slide # 8
Most primitive plants
Found in moist, shady areas
NO vascular (transport) system
Small size due to no vascular tissue
No true roots, stems, or leaves
Needs water for reproduction.
Reproduces using spores, -a water-proof single cell that can grow into a new organism.
Most common example: Mosses
Slide # 9
Spores form inside the capsule.
Notice the problem of nutrient separation into air and soil is solved with underground and above ground parts. (Although NO TRUE roots, stems or leaves are present)
Ferns use spores
The Fern - a seedless vascular plant
There are 11,000 species of ferns.
ADVANTAGE: Developed reproductive strategies that do not need water:
The two Seeded Tracheophyte groups are divided by whether or not they have enclosed seeds -protected inside a fruit or if seeds are exposed to the environment.
Ferns use spores
“naked” or exposed seeds
Flowers produce fruit w/ enclosed seeds
Slide # 16Gymnosperms-Conifers
Maple seeds: Winged fruit
Burdock: Spiny fruit
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