Cell wall is absent in which one of the following organisms?

The cell wall is a structural layer surrounding the cell membrane that provides protection and rigidity. It is present in bacteria, where it is typically composed of peptidoglycan [1]. Diatoms, a type of algae, possess unique cell walls called frustules made of crystallized silica. Mushrooms, which belong to the kingdom Fungi, have cell walls primarily composed of chitin [1]. In contrast, animal cells lack a cell wall entirely, possessing only a flexible plasma membrane [1]. Tapeworms (Taenia) are multicellular parasitic animals belonging to the phylum Platyhelminthes. As members of the animal kingdom, their cells do not have cell walls [1]. This absence of a rigid wall allows animal cells greater flexibility compared to the cells of plants, fungi, and most microorganisms [1]. Therefore, among the given options, the tapeworm is the only organism that lacks a cell wall.

Sources

1. [1] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 2: The Invisible Living World: Beyond Our Naked Eye > 2.5 Why Is Cell Considered to Be a Basic Unit of Life? > p. 24