What distinguishes a chemical change from a physical change?

You arrive late to a biological seminar. however, just as you enter the room, you hear the speaker referring to the "five-prime end" and the "three-prime end" of a macromolecule. immediately, you know that they are talking about a: ]

Which of the following types of pollution is most responsible for large numbers of deaths worldwide because of unsafe drinking water? (a) nutrient pollution (b) thermal pollution (c) pathogen pollution (d) sediment pollution

There are few cells in the body that do not undergo mitosis: most somatic cells divide regularly, some more than others. take for example the cells that line the digestive tract. these cells must be frequently replaced because they are constantly eroded by the movement of food through the tract. what mechanism(s) is/are in place to ensure that these cells are exact copies of the mother cell