Question

multiple choice question
animals with ______ have anterior (head) and posterior (tail) ends.
o asymmetry
o bilateral symmetry
o pentaradial symmetry
o radial symmetry

Explanation:

• Asymmetry: Animals with asymmetry lack a defined symmetrical pattern and do not have distinct anterior and posterior ends.
• Bilateral symmetry: In bilateral symmetry, there is a single plane of symmetry. This allows for the development of distinct anterior (head) and posterior (tail) ends. The head often has sensory organs concentrated there, which is an advantage for forward - moving animals.
• Pentaradial symmetry: This is a type of radial symmetry (specific to echinoderms in adults). In radial symmetry (including pentaradial), there is no clear anterior - posterior differentiation. The body parts are arranged around a central axis, and there is no distinct head or tail in the traditional sense.
• Radial symmetry: Animals with radial symmetry (like cnidarians) have body parts arranged around a central axis. They do not have a well - defined anterior (head) and posterior (tail) as their symmetry is based on multiple planes of symmetry around the central axis.

Answer:

B. bilateral symmetry