if africa and south america split apart tens of millions of years ago, would their shorelines be the best indicators of the shapes of the original pieces or the true extent of either continent? what factors other than rifting and sea-floor spreading could have modified the shape of the current shorelines?

from my research i have to the conclusion that decomposers, such as fungi, bacteria and invertebrates, play a critical role in nutrient cycling and without them the earth's ecosystem may not support life as we know it. elements such as carbon, nitrogen and phosphorus exist in limited amounts on earth, although huge amounts of carbon are being released into the atmosphere from underground sources now by humans. it is still extremely important that other nutrients be retained by the process of re-use. decomposers are organisms that are able to chemically break down dead material and make these elements available for use by other organisms. without this breakdown of dead material, dead bodies would pile up. so decomposers also play a role in clean up also. without them, life might not continue as we know it and dead material would overwhelm the earth.    

the alkaline earth metals (beryllium (be), magnesium (mg), calcium (ca), strontium (sr), barium (ba), and radium (ra)) are a group of chemical elements in the s-block of the periodic table with very similar properties: shiny. silvery-white. hopefully this ? i didn't fully understand the question

well this my answer.

releases oxygen is a light-independent reaction and so is (fixes carbon dioxide. light-dependent reaction takes place in the stroma and lights dependent reaction take place in the grana, light-dependent reactions produce atp. and last but not least, light dependent reactions produces glucose.

hope it : )

this website has a good chart outlining your exact question