Question

Which one of the following categories of animals, is correctly described with no single exception in it?

(a) All sponges are marine and have collar cells.

(b) All mammals are viviparous and possess diaphragm for breathing.

(c) All bony fishes have four pairs of gills and an operculum on each side.

(d) All reptiles possess scales, have a three chambered heart and are cold blooded (poikilothermal).

Answer 1

Correct option: (a) All sponges are marine and have collar cells.

Explanation:

All sponges are marine and have collar cells without any exception. Sponges are animals of the phylum Porifera. They are multicellular organisms which have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like substence sandwiched between two thin layers of cells.