Final answer:
The plane that divides an animal into equal right and left portions is called the midsagittal plane, which is important in the study of anatomy.
Step-by-step explanation:
In the context of anatomical planes, the plane that divides an animal into equal right and left portions is known as the midsagittal plane. This plane runs vertically down the body, creating symmetrical halves on either side. It is important to understand this concept, as the midsagittal plane is a fundamental aspect in the field of anatomy, helping to describe locations and orientations of different body parts in relation to each other.