Practice Questions

Fungi utilize chitin (a polymer of N-acetylglucosamine) for structural support, while plants rely on cellulose.

The interlaced arrangement of cellulose microfibrils leaves large physical pores that allow water and small solutes to diffuse freely.

The spindle apparatus, built from tubulin heterodimers, attaches to kinetochores to pull chromosomes to opposite poles in all eukaryotic cells.

The secondary wall is thick and contains dense cellulose and lignin, providing structural reinforcement to mature, non-growing plant tissues.

The primary cell wall is laid down by expanding cells; it is thin, extensible, and flexible, accommodating cell growth and elongation.

Elaioplasts are specialized, non-pigmented plastids dedicated to storing lipids and essential fatty oils inside plant seeds or leaves.

Apoptosis is a highly regulated programmed cell death mechanism central to animal development, tissue homeostasis, and defense.

The middle lamella is rich in pectin salts (calcium and magnesium pectates), which cross-link to form a sticky, cementing extracellular layer.

Without an external wall to anchor its shape, an animal cell losing water collapses completely, shriveling into a wrinkled, crenated morphology.

Plant cells lack discrete centrioles but possess diffuse, membrane-associated MTOCs that organize the cytoskeletal tracking networks.