There are different categories you can pick from example Predation
The mass of a tree is primarily carbon. The carbon comes from<span> carbon dioxide used during photosynthesis. During photosynthesis, </span>plants<span> convert the sun's energy into chemical energy which is captured within the bonds of carbon molecules built from atmospheric carbon dioxide and water.</span>
<span> They are unable to pass through the plasma membrane and have different methods of action. They attach to their receptors in the target cell surface and influence activity within the cell through cytoplasmic intermediates called second messengers. </span>
<span>The two most important messengers are cAMP and inositol triphosphate. </span>
<span>Cyclic AMP: ATP is converted into cAMP after a series of reactions on the plasma membrane following the attachment of the hormone to the membrane. cAMP relays the signal from the membrane to the metabolic machinery of the cytoplasm. </span>
<span>Inositol Triphosphate: Involves the use of Ca+2 that regulates cellular protein activity.
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Hope this helps !!!^_~!!!
Breaks down over time and becomes dirt
According to kagmi on yahoo these are three lines of evidence that support the theory of evolution.
The fossil record shows the existence of billions of extinct species. It also shows a clear progression from one species to the next; there are many "transitional fossils," such as the archeoptryx (probably spelled that wrong, lol) which is clearly an intermediate in the evolution of dinosaurs into birds.
<span>Biogeography shows the distribution of species, providing further support that different species can and do evolve from common ancestors. Australia has many species of marsupials not found on other continents, for example; this implies that these species may have shared a common ancestor which lived on Australia when it was separated from the other continents by continental drift. </span>
<span>Molecular biology allows us to analyze genes and proteins down to the very molecules that make them up. This reveals many similarities and differences between organisms not readily apparent to the naked eye. We can see, for example, that humans share the vast majority of their DNA with all mammals; slightly less with reptiles; slightly less with amphibians, and so on. We find that species' DNA sequences match up well with the fossil record in terms of how closely related the species are. </span>