Question

Cnidarians and ctenophores have which of the following common features?
A. Presence of mesoglea
B. Carnivory
C. Bioluminescence
D. All of the above

Answer 1

Hint: The phylum Cnidaria includes animals showing radial or biradial symmetry and are diploblastic, which means they develop from two embryonic layers. The Ctenophora comprises a phylum of invertebrate animals which lives in marine water worldwide. These are notable for the groups of cilia that they use for swimming, and are the largest animals to swim using the help of cilia.

Complete answer:
Option A Presence of mesoglea: Tissues that are found in cnidarians like coral or jellyfish that functions as a hydrostatic skeleton are termed as mesoglea. These are related to but are distinct from mesohyl, which generally refers to the tissues that are found in sponges. Ctenophores also have a thick layer of mesoglea.
Hence option A is correct.
Option B Carnivory: Cnidarians are predaceous carnivores which use their stinging tentacles to capture their prey such as things that are very small such as plankton or the things that are much larger than them like fish. Similar to the cnidarians, ctenophores are also carnivorous predators and eat a variety of things like fish eggs, small animals, larval animals, cnidarians such as jellyfish, and even other ctenophores.
Hence option B is also correct.
Option C Bioluminescence: A common phenomenon seen in many deep-sea animals is bioluminescence and is widespread among the Cnidaria. Most of the ctenophores are also bioluminescent, but that light which usually is blue or green, can only be seen in darkness.
Hence option C is also correct.
Option D All of the above: Since options A, B and C are correct.
So, option D is the correct answer.

Therefore, Option D All of the above is the correct answer.

Note:
Other similarities between cnidarians and ctenophores are: both are of biradial symmetry. Both of them lack organ systems and are of simple organization. Arrangements of different structures in both of them are in the oral-aboral axis. Both cnidarians and ctenophores have branched coelenteron and both had the presence of gelatinous mesoglea. They also have a net type nervous system.