Aug. 30th & Sept. 1st; Introduction & Plant Diversity/Evolutionary History

In this course we will cover the Basic Botany Core Concepts including; Plant Phsiology, Anatomy, Life History, and Ecology. The main goal is to tailor this course to what we want to learn and create an open source webpage that compile our research to teach others about different aspects of Botany.

KINGDOM : Plantae

What makes a plant a plant?

There are different traits that are associated with plants. These traits include:

Photosynthesis in double membrane organelles called chloroplasts, they are multicellular, and  they have cell walls made of cellulose.

We can further explore the Plantae Kingdom by looking at the Phylogeny

 

We can tell by fossil records that the first photosynthetic organisms were the cyanobacteria in the mid archaeon eon.
The first land plants evolved after the cambarian explosion at approximately c450 M.A.

The advantages to colonizing land:
No competition with other photsynthetic things and no predators.

The Challenges of moving to land:
Plants now needed to fight against gravity, new was of dispersal for reproduction had to be aquired, the chance of dehydrationg needed to be overcome, and a mode of transportation for water and nutrients to be moved within the system needed to be derived.

Adaptations that were made include:
1. A waxy cuticle and stomata on plants leaves and stems.
The cuticle prevents water lose, and the stomata allows CO2 to pass through for photosynthesis.

2.Gametangia are found in algae, ferns, and some other plants. They are protective chambers of sterile cells wher egametes are produced.

3.Embryos in a protective structure developed from female gametangia.

4. Vasculate Tissues were adaptive.

5. Mutualistic relationships with the fungus, mycorrhizea, was formed as the funfus pulled in more nutrients for the plant.

6.Lignin and cellulose were adaptive polymers that added rigidity to plant structure.

7. Seeds with hard coating to protect the developing embryo

8. Fruit and Flowers were a way to get animals to help with dispersal

800px-plant_phylogeny
Maulucioni, Phylogenetic plant tree, showing the major clades and traditional groups. Monophyletic groups are in black and paraphyletics in blue. 13 February 2016

Examining the phylogenetic tree the first plant group is Non-vascular plants. Node traits include Cuticle/Stoma formation and Mutualistic relationship with mycorrhizae. Given by its name Non-vascular plants have no vascular system and include Bryophytes, such as; moss, liverworts, and hornworts. They have no true roots and absorb nutrients across their whole body. The lack of lignin in the plant makes it soft and squishy as opposed to ridgid. They are good at tolerating water lose.

The next node in the tree sections off Seedless Plants. Node traits include vascular tissue and lignin. The Seedless Vascular Plants include Horsetails and Ferns. Vascular tissue can be divided into two categories, xylem and phloem. Xylem moves water and nutrients into the plant and phloem moves them out. These terms will be described more in depth in future lessons.

Gymnosperms fall under seeded plants and the node trait includes production of seeds. the gymnosperms produce “naked seeds.” These seeds are not packafed in fruit like angiosperms.

Angiosperms are also under the seeded plants and the node trait is the formation of flowers and fruits.

Plant Evolution History

Part 1

Part 2

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