Like animals, plants inherit ways of responding to their surroundings. roots grow down toward water. stems grow up toward the sun. leaves grow toward light, and vines may climb up a tree trunk. these traits are passed from parents to offspring by

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.