Final answer:
The term describing something not visually the same on both sides of a central line is a) asymmetrical.
Step-by-step explanation:
The term that describes something that is visually not the same on both sides of a central line is a) asymmetrical.
This is in contrast to bilaterally symmetric, where a plane cut along its longitudinal axis would produce equal halves that are mirror images of each other. Examples of asymmetrical organisms are those with no plane of symmetry, meaning no matter how you divide them, they cannot produce two halves that mirror each other. Conversely, organisms with bilateral symmetry have a body plan that allows for a single unique plane of symmetry, creating two mirror-image sides.