What is classification? Why is it necessary to classify animals and plants?​

Explanation:

Scientists use Taxonomy, the science of classifying living things, in order to make sense of biodiversity and how living things are related. For example, the classification of species is important in light of a changing environment because it helps scientists keep track of endangered species and what new species were formed because of the environmental change.

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.