Question

how the mucilagineous sheath is formed in alga​

Answer 1

Answer:

The image below shows a desert community in the canyonlands area of Utah, USA. This dryland community (top left; comprising saltbush, Pinyon pine, Utah juniper, Indian ricegrass) and all the animals it supports depend on the pioneer role of a microbial community termed the cryptobiotic crust (also known as microbiotic or cryptogamic crust). These microbial communities initially form an inconspicuous grey-brown covering of the sand surface (top right), consisting of fungi, cyanobacteria and lichens, but in later stages of development (after 50 years or more; centre right) the crusts form small "humps" on which mosses grow.