When an animal has polarity of anterior and posterior ends, it is said to exhibit ____________
A. Radial symmetry B. Bilateral symmetry C. By-radial symmetry D. Radial-bilateral symmetry
Correct Answer: B
Explanation
Symmetry refers to the arrangement of body structures in relation to the axis of the body. In bilateral symmetry animal is divided through one plane (which passes through one the midline of the body) to produce roughly equivalent right and left halves that are mirror ages. A bilaterally symmetrical animal has three axes, each at right angles to the other two; an anterior posterior axis extending from head to tail, a dorsoventral axis extending from back to belly, and a left - right axis extending from side to side.
