Some cats will lick Vaseline off a spoon. Or, if you smear it on the cat's nose or front leg below the elbow, she'll lick it off. Some cats will also eat Vaseline mixed into tuna.ome cats will lick Vaseline off a spoon. Or, if you smear it on the cat's nose or front leg below the elbow, she'll lick it off. Some cats will also eat Vaseline mixed into tuna.
Concept 17 A gene is made of DNA. In the 1920s, experiments showed that a harmless strain of bacteria can become infectious when mixed with a virulent strain of bacteria that had been killed. The dead bacteria apparently provide some chemical that transforms the harmless bacteria to infectious ones.
DNA tells a cell how to make proteins through the genetic code. Both DNA and proteins are long molecules made from strings of shorter building blocks. While DNA is made of nucleotides, proteins are made of amino acids, a group of 20 different chemicals with names like alanine, arginine, and serine.