Which of the following statements is without exception for sponges? (a) They all have calcareous spicules. (b) They have high regenerative power. (c) They are found only in marine water. (d) They are all radially symmetrical
Option B Sponges may have calcareous or siliceous spicules. All sponges are not marine, some are freshwater living also. Sponges may be asymmetrical or bilaterally symmetrical, besides being radially symmetrical. So, these characters are with exception. The character without exception is the regenerative power of sponges. All sponges have a good power of regeneration. They can regrow any part of the body lost or cut off. Small fragments can grow into a complete sponge