Prokaryotes:
* Yes, most prokaryotes have cell walls.
* Function: Provides structural support, protection from osmotic stress, and helps maintain cell shape.
* Composition:
* Bacteria: Primarily peptidoglycan, a unique polymer made of sugars and amino acids.
* Archaea: More diverse, with varying compositions including pseudopeptidoglycan, proteins, and polysaccharides.
Eukaryotes:
* It depends on the type of eukaryotic cell:
* Plants: Yes, they have cell walls made primarily of cellulose, a complex carbohydrate.
* Fungi: Yes, they have cell walls composed of chitin, a tough polysaccharide.
* Animals: No, animal cells do not have cell walls. Their external structure is provided by a cell membrane and sometimes an extracellular matrix.
* Protists: Some protists have cell walls made of various materials, including cellulose, silica, or calcium carbonate. Others lack cell walls altogether.
In summary:
* Prokaryotes generally have cell walls.
* Eukaryotes have cell walls in some cases (plants, fungi), but not in others (animals).
