You are a sports coach for the cross county running team and part of your job is to evaluate and recommend which hydration drink the team should use. when athlete consume hydration drinks, the water is absorbed by special cells that line the intestinal tract, (these cells have a salt concentration of 6%). there are four types of solutions available to choose from. which drink is the best option for hydration of your runners? g2 - a hypotonic solution that contains 1% dissolved salts hydrapure - an isotonic solution that contains 6% dissolved salts gatorade - a hypertonic solution that contains 12% dissolved salts

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.