1. Plant Evolution and Classification
Chapter 28

2. Adapting to Land
The ability to prevent water loss: cuticle- waxy protective covering (also keeps our CO2)
Three adaptations allowed plants to thrive on land.
Cutilce-waxy protective covering used to prevent water loss; also keeps out CO2.
Small plants that had stomata were able to survive.

3. Adapting to Land
2. The ability to reproduce in the absence of water – spores and seeds

4. Spore vs seed
A spore is haploid reproductive cell surrounded by a hard outer wall. Allowed the widespread dispersal of plant species.
A seed is an embryo surrounded by a protective coat. Some seeds contain endosperm- tissue that provides nourishment for the developing plant. Seeds are more effective for dispersal than spores
ex. Maple tree seeds

5. Adapting to Land The ability to absorb and transport nutrients –
Vascular tissue – xylem and phloem .
botit.botany.wisc.edu/

6. Vascular Tissue
Vascular tissue transports water and dissolved substances from one part of the plant to another. It also provides support.
Xylem- transports inorganic nutrients one way: roots to leaves
Phloem- carries organic compounds/some inorganic compounds any way, any where
Plants on land get their nutrients by absorbing them from the soil.
Vascular tissue also helps support the plant

7. Nonvascular vs. Vascular
Classifying Plants
Nonvascular vs. Vascular
On page 564, you can see the table that has all 12 phylums of plants. They can be divided into 2 main catagories: nonvascular and vascular.

8. Seedless Vascular Plants
Nonvascular Plants
Seedless Vascular Plants
Gymnosperms
Angiosperms
Flowers
Seeds
Harden Vascular Tissue
This is a hypothesis for the evolutionary relationships between plants and green algae.
Reproduction by Spores
Algal Ancestors

9. Nonvascular plants
Have neither true vascular tissue nor true roots, stems, or leaves.
3 phyla
Bryophyta
Heptophyta
Anthocerophyta

10. Vascular Plants Vascular, seedless Vascular, seed Whisk ferns
Club mosses
Horsetails
Ferns
Vascular, seed
Cycads
Ginkgoes
Conifers
Gnetophytes
Flowering plants
Monocots
Dicots
Gnetophytes are seed-bearing plants that can grow as shrubs, trees, or vines and share similarities with both gymnosperms and angiosperms.

11. Vascular Plants Have vascular tissue and true roots, stems, and leaves
pky7thgradescience.pbworks.com

12. Seedless vascular plants
Ferns – dominated the earth until about 200 million years ago.

13. Vascular Seed Plants
Produce seeds for reproduction – embryo with a nutrient supply
Have a greater chance of reproductive success
When conditions are right the seed sprouts, or germinates
Inside the tough, protective outer coat of a seed is an embryo and nutrient supply.
There are 2 main groups of seed-bearing vascular plants: gymnosperms & angiosperms.

14. Gymnosperms 4 phyla Produce naked seeds
Seeds are not enclosed and protected by fruits.
Most are evergreen and bear their seeds in cones
A cone is a reproductive structure composed of hard scales. The seed lie open on the surface of the scales.

15. Angiosperms
1 phyla – produces seeds that are enclosed and protected in fruits – called flowering plants
Cones serve some of the same functions for gymnosperms that flowers serve for angiosperms.

16. The Evolution of Angiosperms
In many angiosperms, seeds germinate and produce mature plants, which in turn produce new seeds, all in one growing season.
Gymnosperms often take 10 or more years to reach maturity and produce seeds.
Angiosperms have the advantage over gymnosperms because they are able to reproduce new seeds in one growing season, whereas gymnosperm take a long time to mature.

17. The Evolution of Angiosperms
The fruits of flowering plants protect seeds and aid in their dispersal.

18. The Evolution of Angiosperms
Angiosperms also have a more efficient vascular system and are more likely to be associated with mycorrhizae than gymnosperms.
Mycorrhizae are symbiotic associations that form between the roots of most plant species and fungi. These symbioses are characterized by bi-directional movement of nutrients where carbon flows to the fungus and inorganic nutrients move to the plant, thereby providing a critical linkage between the plant root and soil.

19. The Evolution of Angiosperms
Angiosperms have an advantage by using animal pollination rather than the less-efficient wind pollination used by gymnosperms.

20. The Evolution of Angiosperms
Angiosperms are more diverse than gymnosperms, so they occupy more niches.
Aquatic
Epiphytic
Parasitic

21. Monocots and Dicots Based upon the number of cotyledons.
Cotyledon: seed leaves in a plant embryo
Flowering Plants are divided into Monocots and Dicots. The primary feature that distinguishes these 2 classes is the number of cotyledons.
*Note that gymnosperms have 2 or more cotyledons.