Question

Water current in leucosolenia is produced by
A. Pinacocytes
B. Choanocytes
C. Archaeocytes
D. None of the above

Answer 1

In the Porifera phylum, there is a genus of branched sponges called Leucosolenia. The outer wall of Leucosolenia species consists of a layer of flat, squamous cells called pinacocytes. Choanocytes have little finger-like processes called flagella that move back and forth to move water through the sponge. Between the inner and outer layers is a gel-like matrix called mesoglea. Mesoglea contains freely moving cells called amoebocytes. It also contains a silicone structure that supports the skeleton in the body.

Complete answer:
The inner epithelium consists of a layer of choanocytes, forming the mucous membrane of the spongocoel, also called the stomach. Choanocytes are oval cells with flagella that originate from basal granules and are surrounded by almost transparent contractile rings of protoplasts. The destruction of the choanocyte whiplash cells keeps the water flowing in the body of the fungus.
The outer epidermal layer consists of pinacocytes. which are thin, flattened cells, scale-like known as pinacocytes which lie with the rims touching and forming a single layer of cells, the pinacoderm. This layer bureaucracy the outer protecting masking of the tube. A pinacocyte has thin highly contractile margins and contains a principal bulging having a nucleus.
Mesenchyme is the middle layer between choanoderm and pinacoderm. The mesenchyme is a thin, gel-like layer. It is secreted by choanocytes and holds in place the skeletal elements of calcium carbonate called spicules or sclerites. The mesenchyme is an amoeboid cell with several freely moving amoebocytes. These cells contain RNA and reproduce naturally. These cells can lead to different types of cells, which is why totipotent work. They can produce pinacocytes, choanocytes, cholecytes, sclerocytes or scleroblasts and germ cells. Spicules are needles, that is, crystalline, such as monaxon, tetraxone (four-arm) or triaxone.
Under normal conditions, all the holes in the sponge are wide open and water flows in through the ostia and out with the help of the osculum. The flow of water(water current) is caused by churning (flagella)of choanocytes. This stream carries food, promotes gas exchange and removes metabolic products.

Hence, the correct option is (B).

Note:
The structure of the sponge is designed so that a stream of water slowly flows through the area of ​​choanocytes. Food includes planktonic microscopic animals and plants, as well as organic matter. Food particles seem to stick to the rings or get stuck between the rings of adjacent choanocytes. Food particles are absorbed by choanocytes or migrate to amoebocytes just below.