Question

Which of the following is a mismatched pair?
A. Scales - Reptilia
B. Comb plates - Mollusca
C. Choanocytes - Porifera
D. Parapodia - Annelida

Answer 1

Hint: Scales, comb plates, choanocytes and parapodia are various exclusive features found in organisms belonging to various kingdoms, while Reptilia is a class included in kingdom Mammalia just like kingdom Mollusca, Porifera and Annelida.

Complete answer: The tentacles of Ctenophores have meridional bands like structures with transversely arranged combs. Eight ciliary plates on the body serve the function of locomotion, like a comb. The eight comb rows that orally extend from the vicinity of the statocyst act as locomotory organs. Every comb row consists of a series of very wide transverse cilia plates, fused at the base, called combs. They are ctenophore's exclusive feature and not molluscs.
a) Scales have various shapes and sizes and are mainly useful in protecting reptiles from the outside world. They primarily cover reptile skin to help maintain moisture and alter surface characteristics to provide protection for camouflage such as roughness. The skin acts as a defensive boundary against the external environment. Scales consist of both the epidermis and dermis and the scales are epidermal in ancestry themselves. The epidermal skin layer, in the case of reptiles, consists of cornified cells.
b) Choanocytes are the cells that are found to line the inside of sponges of asconoid, syconoid, and leuconoid body types. Choanocytes are generally referred to as Porifera collar cells. The inner lining of sponges that have a central flagellum is produced by these cells. Syconoid sponges form radial canals in them. Their purpose is to filter particles into the spongocoel from the water that enters.
c) Para refers to lateral outgrowths or protrusions from the body, beyond or beside + podia, feet, or parapodia). In annelids, where they are paired, un-jointed lateral outgrowths bearing the chaetae, Parapodia are mainly found.
Hence, the correct answer is option B.

Note: All molluscs have a strong muscular organ called the foot, with the exception of cephalopods, from which muscle fibres pass in all directions. A gastropod's foot is a flat device used for crawling. This foot is generally the same size as the shell's opening in shelled molluscs. The foot is both a retractable organ and an extendable one.