Plant Diversity. The Evolution and Classification of Plants. Why should we care about plants, at all?. Carbon dioxide levels. Indicators for ground level pollution, long before animals. Japan/ radioactive food…. But…. Kudzu- invasive. Did you know…….
The Evolution and Classification of Plants
Oak trees do not reach sexual maturity with acorns until they are fifty years old or older
Bamboo can grow up to three feet in a 24 hour period.
The squirting cucumber (Ecballium elaterium), when brushed by a passerby, ejects its seeds and a stream of poisonous juice that stings the skin
Fruits have become more expensive because we have killed more bees (and birds) with insecticides….
True or False
6. Some plants lose their leaves in the winter because it gets too cold
7. Plants know their up from their down
8. Plants have hormones the same way we do
9. Leaves are different on the two sides
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
Have a protective layer – cuticle (waxy outer layer) to keep from drying out
2. Have body parts extending into both air and soil (roots)
3. Have leaves – photosynthesis takes place on tops of leaves
4. Develop a vascular system to transport resources in plant
5. . Specialized structures for reproduction including spores & sex cells (seeds) that do not dry out
In response to seasons …
In response to stimuli …
They grow towards light, which is usually away from where gravity is trying to pull them …
Most primitive plants
NO “pipes” (vascular system)
Small size due to no vascular tissue
No true roots, stems, or leaves
Most common example: Mosses, liverworts
6. Need WATER to reproduce
7. Reproduction can be sexual or asexual
8. Tend to be located near water or in moist/shady places.
NO TRUE roots, stems
Contains vascular tissues.. But not much else!
There are 11,000 species of ferns.
3. Has underground stems, roots, & large leaves called fronds.
4. Reproduction can be sexual or asexual
5. Example: Ferns, horsetails, club mosses
Maple seeds: Winged fruit
Burdock: Spiny fruit