LOCAL ENVIRONMENT ISSUE: People dump a lot of trash in the sea, and the sea creatures living there goes through a lot of trouble to live with all the muck getting in them. Of course, don't write it like that in your assignment - you'll get told off for the straight forwardness.
Archaean cell wall don't have peptidoglycan, yet they may have <em>, polysaccharides, glycoproteins, or protein-based cell dividers </em>
Bacterial cell walls are made of peptidoglycan (likewise called murein), which is produced using polysaccharide chains cross-connected by abnormal peptides containing D-amino acids
