Which of the following are three common characteristics of echinoderms?
a. tube feet, circulatory system, body symmetry
b. marine-dwellers, endoskeletons, water-vascular system
c. bilateral symmetry, ossicles, respiratory system
d. mouths, protosomes, body symmetry
B?
Thank you!
Correct! Three common characteristics of echinoderms are:
b. marine-dwellers, endoskeletons, water-vascular system
To arrive at this answer, we can break down each option:
a. Tube feet, circulatory system, body symmetry: While echinoderms have tube feet and body symmetry, they do not possess a circulatory system. Therefore, this option is not correct.
b. Marine-dwellers, endoskeletons, water-vascular system: This option is correct. Echinoderms are exclusively marine-dwellers, meaning they live in the ocean. They have endoskeletons, which means that their skeletal structure is located internally. Additionally, echinoderms have a unique hydraulic water-vascular system, which they use for movement and other functions.
c. Bilateral symmetry, ossicles, respiratory system: Echinoderms do not have bilateral symmetry (they have radial symmetry) or a respiratory system. Ossicles, which are small calcified structures, are indeed present in echinoderms, but this is not one of the most common characteristics shared by all echinoderms. Therefore, this option is not correct.
d. Mouths, protosomes, body symmetry: Although echinoderms do have mouths and a specific type of embryonic development known as deuterostome, they do not exhibit protosome embryonic development. Additionally, their body symmetry is radial, not bilateral. Therefore, this option is not correct.