[Campbell Biology P.729] Based on the description of radial and bilateral symmetry, which st... | Practice Question
Based on the description of radial and bilateral symmetry, which statement is true?
A: Radial animals, unlike bilateral animals, typically possess distinct anterior (front) and posterior (back) ends.
B: Bilateral symmetry allows for a single imaginary slice to divide the animal into mirror-image halves, and sensory organs are often concentrated at one end.
C: Both radially and bilaterally symmetrical animals can be divided into mirror images by any slice passing through their central axis.
D: Sponges are described as exclusively exhibiting radial symmetry, with their cells arranged in a regular pattern around a central axis.
Explanation
The text states that in bilateral symmetry, 'Only one imaginary slice... divides the animal into mirror-image halves, referred to as a right side and a left side.' It also notes that 'In nearly all bilateral animals, eyes and other sensory organs are concentrated in the head end of the body.' This confirms option B.