Living things are made of types of molecules, known as macromolecules.
There are four major classes of biological macromolecules:
carbohydrates
lipids
proteins
nucleic acids
Each of these types of macromolecules performs a wide array of important functions within the cell; a cell cannot perform its role within the body without many different types of these crucial molecules. In combination, these biological macromolecules make up the majority of a cell’s dry mass. (Water molecules make up the majority of a cell’s total mass.) All the molecules both inside and outside of cells are situated in a water-based (i.e., aqueous) environment, and all the reactions of biological systems are occurring in that same environment.
4.6 million years ago the earth had less green house gasses so the atmosphere was cooler rather than hotter.
Answer is in the file below
tinyurl.com/wpazsebu
Drinking through a straw shows fluid flowing from high pressure to low pressure in 2 ways. The first is how it shows high pressure as you stuck on the straw. This increases the pressure and brings the fluid to your mouth. If this pressure is kept you can successfully pick up the straw filled with water and have none come out. This demonstrates low pressure when you stop ducking and the fluid falls back down the straw into your cup.
