BIO 2137 Lecture Notes - Lecture 14: Monocotyledon, Endodermis, Cell Membrane
15 Nov 2016
School
Department
Course
Professor
Document Summary
All plants have a primary cell wall outside their plasma membrane. Provide support and shape, but allows cell to grow in size. Deposited inside the primary cell wall after cell has stopped growing. Areas with thinner primary and no secondary cell wall = pits. Most abundant type of cell in most plants. Perform a variety of functions, such as food storage, photosynthesis, secretion, wound healing, etc. Between epidermis in stems, petioles, and around veins in eudicots. Supporting tissue for growing stems, leaves, and floral parts, and for herbaceous organs that undergo little or no secondary growth. Have thick secondary cell walls that provide support to the plant. They contain lignin, the substance that makes wood hard are bundles of long sclerenchyma cells. Lignin in cell walls provides support, impermeability to water. Xylem also contains parenchyma cells and fibers (sclerenchyma) for storage and support. Tracheids: evolved first, present in all vascular plants.
