Question

In an experiment, the sponge is squeezed through silk cloth and allowed to stand undisturbed in an appropriate medium. It is performed to prove that
A.The sponges are multicellular.
B.The cells are loosely arranged.
C.The cells are so small that they can be squeezed through a cloth.
D.The sponges are non-living.

Answer 1

Hint:Sponges have a cellular level of organization with asymmetrical and diploblastic bodies. Sponges are sessile. The canal system helps in nutrition, respiration, excretion, and reproduction.

Complete answer:
Sponges belong to phylum Porifera. The study of sponges is known as Parazoology. Sponges have a cellular level of organization. They are sedentary, sessile, and found attached to the rocks. Sponges are asymmetrical and are diploblastic. Their body wall consists of a dermal layer(pinacoderm) and a gastral layer(choanoderm). In between these two is a non-cellular mesophyll layer.
Skeletons are made up of calcium carbonate or silica spicules or spongin fibers or absent. The water canal system is the characteristic feature of sponges.
Sponges have totipotent cells called archaeocytes, because of which they have regeneration power.
When a sponge is passed through a silk cloth, all the cells will separate. Separated cells will reaggregate and as they have regeneration power, they will develop into many new smaller sponges.

So, the correct option is B. the cells are loosely arranged.

Note:Sponges are filter feeders, they store their food in thesocytes. Respiration is through the body’s surface. The excretory product of sponges is ammonia. Porifera is the only phylum in the Animal Kingdom, which is without any nerve cell. Asexual reproduction is by gemmules or by regeneration.
Archaeocytes produce gonads and development is indirect.