Cacti typically grow in very dry climates with infrequent rainfall when it does rain the rain usally only penetrates a few inches into the soil which adaptation is most likey to a cactus survive in the dry climate

Its waxy outside keeps the water in and everything else out.

the core of the sun is so hot and there is so much pressure, nuclear fusion takes place, hydrogen is changed to helium. nuclear fusion creates heat and photons. when the heat reaches the earth it warms the molecules of the atmosphere, and they warm other molecules and so on.

this protocol provides a detailed procedure for chromatin immunoprecipitation (chip) to study the dna-protein interactions.