GENERAL HISTOLOGY

Detailed explanation-1: -So, the given statement is true.

Detailed explanation-2: -Echinoderms are the largest phylum with no freshwater or terrestrial forms. Echinoderm environments must be marine, as in saltwater, for the echinoderm to survive. Within marine environments, the conditions echinoderms live in can vary greatly.

Detailed explanation-3: -Answer and Explanation: The correct answer is (b). Echinoderms do not have gills.

Detailed explanation-4: -Echinoderms are slow animals radically different from us, but they are an evolutionary success. All echinoderms have five-part symmetry. We see the inner workings of sea stars, from their tube feet to their skeleton. Urchins are ferocious herbivores chomping down kelp with their jaws.

Detailed explanation-5: -Echinoderms are marine organisms which means they live in the ocean. They are found in all marine waters on Earth although there are few species living in the Arctic. Many echinoderms are visible on the seashore such as sand dollars, globular spiny sea urchins and asteroids.