Question

Which one of the following statements is wrong?
A. Insects have one pair of antennas
B. Millipedes possess two pairs of appendages in each segment of the body.
C. Prawns have two pairs of antennas.
D. Animals belonging to the phylum Porifera have nematocyst.

Answer 1

Antennae are associated with the first or two fragments of the arthropod head. They fluctuate generally in structure however are constantly made of at least one joint-segment member is any of the homologous body parts that may stretch out from a body portion. a phylum of crude invertebrate creatures involving the sponges

Complete answer:
Bugs are recognized from different arthropods by having three sets of jointed legs; a midsection that is separated into 11 portions. They have one set of antennae on the head. So, option A statement is right.
Millipedes are a gathering of arthropods that are described as having two sets of jointed legs on most body sections. Each twofold legged portion is an aftereffect of two single sections combined. They have two sets (four legs) on each fragment. So, option B’s statement is right.
Prawns have two sets of receiving antennas. The main radio antenna is otherwise called an antenna. It is put close to the base of the eyestalk. The subsequent reception apparatus is arranged imme­diately after the primary radio antenna. It likewise fills in as an excretory organ. So, option C's statement is right.
Cnidarians (Phylum Cnidaria) are diploblastic, i.e., they have two layers of cells — ectoderm and endoderm — with a jellylike mesoglea between them. They have cnidoblasts: specific cells that emit a stinging case called a nematocyst. In this way, the appropriate response is D
Hence, option D is correct.

Note: Porifera is on the whole amphibian, generally marine aside from one family Spongillidae which lives in freshwater. They are sessile and stationary and develop like plants. The body shape is a jar or chamber-like, unbalanced, or radially balanced. The body surface is punctured by various pores, the ostia through which water enters the body, and at least one huge opening, the oscula by which the water exists. The multicellular living being with the cell level of body association. No particular tissues or organs.