Phelloids are
Synonymous to phellem
Lignified cork cells
Suberised cork cells
Non-suberised cork cells
Phelloids are indeed non-suberized cork cells. Cork cells are specialized cells found in the outer bark of woody plants, including trees. They are responsible for the production of cork, which is a protective tissue that helps prevent water loss, mechanical damage, and provides insulation.
Suberin is a waxy substance found in the cell walls of cork cells. It is responsible for making the cork cells impermeable to gasses and liquids. However, in some cases, there may be regions within the cork layer where the cells do not develop suberin, and these cells are referred to as phelloids.
Phelloids lack the suberin coating found in typical cork cells and have different characteristics. They may have a different cell shape, size, and arrangement compared to the surrounding cork cells. Phelloids can serve various functions, including storing water and providing mechanical support.
Hence, the correct answer is option 4.