Katya listed major questions that scientists try to answer when they classify organisms. her list included the following questions: how many living things are there? what are the characteristics that define living things? what additional question would be best for katya to add to her list about classification?

How are living things related?

Explanation:

Classification of the living organisms depends upon the similarities and differences shared with the other group of organisms. Linnaeus is known as the father of biological classification.

Katya trying to study the classification of the living organism. She has included the different questions ob the classification of the living organisms. Katya must include the relationship between the living organisms and their interaction between the other organisms.

Thus, the answer is How are living things related?