Final answer:
A midsagittal plane divides the human body into equal left and right portions, fitting the description of the section through the umbilicus.
Step-by-step explanation:
A plane that divides an animal into equal right and left portions is known as the midsagittal plane. Specifically, the question refers to a section through the umbilicus (navel) that would divide the human body into equal left and right halves, which indeed aligns with a midsagittal plane. It is distinct from parasagittal, which creates unequal right and left halves, the coronal or frontal plane which divides the body into anterior and posterior (front and back) sections, and the transverse plane that divides the body into superior (upper) and inferior (lower) portions.