Suberin is primarily found in which type of tissue within plant structures?

Suberin is a hydrophobic biopolymer that serves as a protective barrier in plants, primarily found in cork tissue and the endodermis. Cork tissue, which is part of the outer bark, provides insulation and protection against pathogens and environmental damage. It is composed of cork cells that are heavily impregnated with suberin, which makes them impermeable to water and gases, helping to prevent water loss.

The endodermis is the innermost layer of the cortex in roots and serves to regulate the flow of water and nutrients into the vascular system. The cells of the endodermis also contain suberin, particularly around their walls, forming a structure known as the Casparian strip. This strip allows the endodermis to act as a selective barrier, regulating what can pass into the vascular tissue.

In contrast, other types of plant tissues mentioned in the other options do not typically contain suberin in significant amounts. Ground tissue and xylem, phloem and epidermis, or meristematic and vascular tissues do not have the same protective and waterproofing qualities imparted by suberin, which is specifically characteristic of cork and the endodermis.