Chapter 20, Problem 3A

Summary Introduction

To write:

About a tough, flexible polysaccharide found in fungi.

Introduction:

Fungi are heterotrophs of a unicellular or multicellular eukaryotic that are decomposers. They are the world's largest and oldest species. Some characteristics in fungi that differentiate them from plants include their hyphae, cell walls, and cross-walls.

Explanation of Solution

Fungi are made of long cell chains. Hyphae tend to be threadlike filaments, without a microscope. Such filaments are the basic structural units that constitute a multicellular fungus' body and are called hyphae. Hyphae expand repeatedly at their tips and branch out to form a netlike mass called a mycelium. In many fungi, cross-walls called septa separate the hyphae into cells. The septa have large pores that allow the flow of nutrients, cytoplasm, organelles, and in some cases nuclei between cells. Chitin is a strong, flexible polysaccharide found in all the fungi's cell walls, and the insect and crustacean exoskeletons. Chitin is among the most abundant organic compounds.

Conclusion

Therefore, it can be concluded that chitin is a strong, flexible polysaccharide that is present in the cell walls of all fungi and septa are the cross-walls that divide hyphae into cells.