Question

Comb plate of ctenophores possess
a. Cilia for locomotion
b. Cilia for filter feeding
c. Teeth for crushing
d. Teeth for filtering

Answer 1

Hint: The tentacles of Ctenophores have meridonial bands that have transversely arranged combs like structures. Comb-like eight ciliary plates on their body serve the purpose of locomotion.

Complete answer:
The ctenophores comprise a phylum of invertebrates that are found in marine water worldwide. They are amongst some of the most beautiful of the oceans' jewels, coming in a wide variety of shapes and sizes. They are free-swimming, soft-bodied, transparent, jelly-like marine animals which have biradial symmetry and comb-like ciliary plates for locomotion. Therefore, they are also known as sea walnuts or comb jellies. They are considered as 'jellyfish' by some but the ctenophores are very different from the true jellyfish (the scyphozoan cnidarians).

Ctenophores are specially characterized by eight rows of cilia, which are used for locomotion. The cilia found in every row are usually arranged to make a stack of combs, also called comb plates, or ctenes. These cilia beat synchronously and propel ctenophores through the water, although some species move with a flapping motion of their lobes or undulations of the body. Many ctenophores also have two long tentacles, but some lack them completely. One more identifying characteristic of ctenophores is bioluminescence produced by beating of the eight rows of locomotory cilia.

Hence, the correct answer is option (A).

Note: Ctenophores, or comb jellies, are one among of the earliest known branching basal metazoan groups, whose phylogenetic position continues to be controversial. They have eight rows of iridescent structures, known as comb plates, that are big multiciliated paddle-like structures used for locomotion and uniquely occur in this group of animals.