Question

After drying, a bath sponge contains
A. Hold Fast
B. Tentacles
C. Spicules
D. Spongin fibres

Answer 1

Hint:-Euspongia is well known as a bath sponge which comes under phylum porifera, a multicellular organism with a body full of pores which enable circulation of water through them. They normally rely on this water circulation and when they are dried up they are only left with spongin fibres. It forms the fibrous skeleton of sponges and when they are dried up they are left only with their skeleton.

Complete step-by-step solution:-
Euspongia is called a bath sponge due to its structure and texture they have got from their family Porifera “Phylum”. They have large pores and ways for circulation of water through them, they generally do not have digestive, nervous or any circulatory systems. The only means of their survival is water circulation through them by which their body gets food & oxygen and is helpful in removal of waste. They possess asexual means of reproduction. But when they are dried up they are left with just its skeleton which is made up of spongin fibres. When a bath sponge gets dried all of its cells get destroyed due to lack of water circulation in them except spongin fibres. Hence our answer for the above mentioned question is (D) Spongin fibres.

Note:- Spongin fibres forms the skeleton of sponges which is a type of modified collagen protein, secreted by spongocytes (sponge cells). Spongin is only responsible for the flexibility of its body. Structurally it is a horny sulphur layer which contains protein and makes up the skeleton of the sponges. A bath sponge is of asymmetric structure with large pores and channels that supports the flow of water through them.