Which class includes sea cucumbers?

Which class includes sea cucumbers?

• A. Holothuroidea
• B. Mollusca
• C. Mammalia
• D. Medusa

Answer: (A)

Sea cucumbers belong to the echinoderms and are placed in the class Holothuroidea. This group is distinguished from other major animal groups by features such as an elongated, cucumber-like body, leathery skin, a reduced internal skeleton, and a mouth surrounded by tentacles that are modified tube feet. They share a water vascular system used for movement and feeding, like other echinoderms, and they exhibit pentaradial symmetry as adults, though their shape is elongated. The other options don’t fit: Mollusca includes animals like clams and snails; Mammalia are mammals with features such as hair and milk production; Medusa is a jellyfish life stage, not a class. Therefore, the class that includes sea cucumbers is Holothuroidea.

Sea cucumbers belong to the echinoderms and are placed in the class Holothuroidea. This group is distinguished from other major animal groups by features such as an elongated, cucumber-like body, leathery skin, a reduced internal skeleton, and a mouth surrounded by tentacles that are modified tube feet. They share a water vascular system used for movement and feeding, like other echinoderms, and they exhibit pentaradial symmetry as adults, though their shape is elongated. The other options don’t fit: Mollusca includes animals like clams and snails; Mammalia are mammals with features such as hair and milk production; Medusa is a jellyfish life stage, not a class. Therefore, the class that includes sea cucumbers is Holothuroidea.