AP BIOLOGY

Detailed explanation-1: -Option (a) collenchyma-It is a group of specialised cells meant for mechanical support. It has the thickening at the corners of the cells which is mainly because of the deposition of pectin and hemicellulose.

Detailed explanation-2: -Collenchyma walls have a similar composition to primary cell walls (Jarvis, 1992). These cell walls surround growing cells and are made up of cellulose microfibrils embedded in a hydrated matrix of complex polysaccharides classified as hemicelluloses and pectins (Cosgrove, 2005).

Detailed explanation-3: -Hemicelluloses include xyloglucans, xylans, mannans and glucomannans, and beta-(1–>3, 1–>4)-glucans. These types of hemicelluloses are present in the cell walls of all terrestrial plants, except for beta-(1–>3, 1–>4)-glucans, which are restricted to Poales and a few other groups.

Detailed explanation-4: -Final answer: Algae have cell walls made up of cellulose, hemicellulose, and pectins.