Plants are:
-Eukaryotic
-Photosynthetic [Photoautotrophs]
-Producers
-Multicellular
-Sexually reproducing
-And have a life history that involves an alternation of a halpliod phase (Gametophyte) with a dipliod phase
Word for word from the Campbell text the characteristics are:
apical meristems;
alternation of generations;
walled spores produced in sporangia;
multicellular gametangia;
multicellular, dependent embryos.
Plant Evolution and its Effects
-Photosynthesis evolved early in the evolutionary history of life, when all forms of life on Earth were micro-organisms. Although the dates are difficult to estimate with any accuracy, the first photosynthetic organisms probably evolved about 3,500 million years ago, and used hydrogen or hydrogen sulfide as sources of electrons, rather than water.
-Cyanobacteria appeared later, around 3,000 million years ago, and changed the Earth forever when they began to oxygenate the atmosphere, beginning about 2,400 million years ago.
-This new atmosphere allowed the evolution of complex life such as protists. Eventually, about 550 million years ago, one of these protists formed a symbiotic relationship with a cyanobacterium, producing the ancestor of the plants and algae.
-The chloroplasts in modern plants are the descendants of these ancient symbiotic cyanobacteria.
A photo of a cynobacteria.
Photosynthesis
6H2O + 6CO2+ Light Energy ----> C6H12O6+ 6O2
-Photosynthesis is a process in plants that converts light energy, water and inorganic compounds into chemical energy and oxygen.
-Photosynthesis occurs in the mesophyll cells of the plant, mainly in the leaves.
-Light and Water enter photosystem II in the chloroplast and then to photosystem I through an electron transport chain.
At Photosystem I Oxygen is released.
-ATP and NADPH are then sent from photosystem I to the Calvin Cycle where they give off ADP and NADP+ to create RuBP, CO enters the cycle and the reactants undergo phosphorylation to produce a -phosphoglycerate.
-Starch, amino acids, fatty acids and sucrose are created.
A Starch molecule.
