When was the "Permian Era"?

Which class of molecules functions as chemical signals? hormones water carbohydrates proteins

How many liters of ethylene glycol antifreeze (c2h6o2), with a density of 1.100 g/l, would you add to your car radiator containing 15.0 kg of water if you needed to protect your engine to - 21.5°c? for water, kf = 1.86°c m -1.

What occurs when a cell engulfs large food particals