The branch of science that includes the study of plants, animals, and the human body is biology.

Here's why:

* Biology is the study of life and living organisms, including their structure, function, growth, evolution, and distribution.

* Botany is a subfield of biology specifically focused on plants.

* Zoology is a subfield of biology specifically focused on animals.

* Human biology or anatomy and physiology are subfields of biology focusing on the human body.

Therefore, biology encompasses the study of all these subjects and more.