1. synthesis reaction
2.reversible reaction
3. decomposition reaction
4. exchange reaction
DNA is tightly wrapped around his tones, then those his tones tightly wrap together to form chromosomes.
Answer;
Models are used throughout science although they are not always accurate.
Explanation;
A scientific model seeks to represent empirical objects, phenomena, and physical processes in a logical and objective way.
Models are central to what scientists do, both in their research as well as when communicating their explanations.
Models allow the scientist to describe objects that are too large or too small to be seen normally, things that don't exist anymore, things that have not been created, and events that occur too slowly or too quickly to be seen. Models also communicate ideas that might be difficult to describe otherwise.