Term
|
Definition
| Occur in the shoot apex. Usually pyramidal in shape. Usually is only one. Usually divide periclinally (parallel to the surface). |
|
|
Term
|
Definition
| The zone directly underneath the central mother zone, and above the rib meristem or pith. |
|
|
Term
|
Definition
| The common tier of the epidermis and the root cap. |
|
|
Term
|
Definition
| Large cells that divide in multiple directions to for the rib meristem. |
|
|
Term
|
Definition
| Forms a short cylinder surrounding the rib meristem. Cells divide in all directions. |
|
|
Term
|
Definition
| The type of corpus directly below the central zone. Enlarges in volume and can form pith. |
|
|
Term
|
Definition
| Consists of a group of initials. No boundary with reference to the derivative regions. |
|
|
Term
|
Definition
| Two regions: Tunica and Corpus. They can be distinguished by their planes of division. |
|
|
Term
|
Definition
| Contains the transitional zone. Less homogeneous than the tunica. Number of cell layers may not be constant. Devides in all directions, enlarges in volume. |
|
|
Term
|
Definition
| Includes a single or multiple outermost layers of cells. Surrounds the corpus. Mostly anticlinal cell division. |
|
|
Term
|
Definition
| Is the region where cell division occurs infrequently. Size is variable but is hemispherical in shape and may contain 500-1000 cells. Excludes the initials for the root cap. |
|
|
Term
|
Definition
| The single tier forming the root cap is called the calyptrogen. |
|
|
Term
|
Definition
| Contain 3 tiers. One at the apex of the central cylinder, one at the cortex tissue, and one directly beneath the rootcap. Become descrete immediately adjacent to the central cells. |
|
|
Term
|
Definition
| Covers the cuticle and is used to reduce water loss. Synthesized in the epidermal cells. |
|
|
Term
|
Definition
| Surround the stoma. Open and close the stoma by increasing water potential and absorbing/losing water from/to the subsidiary cells surrounding the guard cells. Have chloroplasts. |
|
|
Term
|
Definition
| Has multiple cell layers. Covers the plant body protecting it from the external environment. Rare. |
|
|
Term
|
Definition
| Surround the guard cells. Lack chloroplasts. Aid in the opening and closing of the stoma. |
|
|
Term
|
Definition
| 2 major types: glandular and non glandular. May function in insulation, salt removal, and defense. |
|
|
Term
|
Definition
| Occurs as a seperate layer on the outer surface of the epidermis. |
|
|
Term
|
Definition
| Are filled with silica bodies that make the cell very hard. |
|
|
Term
|
Definition
| Have a common origin with the guard cells. |
|
|
Term
|
Definition
| Occur in pairs with silica cells and alternate with elongated epidermal cells. Secondary tissue formed by the cork cambium. Forms outer part of the periderm. Suberized cork cells are air and water proof. Reduce water loss and protect the plant. |
|
|
Term
|
Definition
| Devides to form the two guard cells. |
|
|
Term
|
Definition
| Do not have a common origin with the guard cells. |
|
|
Term
|
Definition
| Partly related ontogenetically with the guard cells. |
|
|
Term
|
Definition
| Forms the guard mother cell. |
|
|
Term
|
Definition
| Elongated perforations arranged in a parallel, ladder-like, series |
|
|
Term
|
Definition
| Food storage and transport of various substances axially. |
|
|
Term
|
Definition
| 2 types: Vessel Elements and Tracheids |
|
|
Term
|
Definition
| Are elongated cells with lignified secondary walls and are dead at maturity. Have both pit pairs and perforations through which vessel elements are longitudinally connected, allowing water to move vertically as well as laterally. Are joined end on end to form vessels. |
|
|
Term
|
Definition
| Outgrowths on parenchyma cells of the xylem. Respond to stressors like drought and infection to block up the tissues to prevent the spread of further damages. |
|
|
Term
|
Definition
| Simple and Multiple perforation plates. Allow water transport through the vessel elements in the xylem. |
|
|
Term
|
Definition
| Are elongated cells with lignified secondary walls and are dead at maturity. Function in water transport. Only can transport water laterally (sideways) through bordered pit pairs in their common walls. Do not have perforation plates on the ends. |
|
|
Term
|
Definition
| Has only simple pits. Is longer and has thicker walls than fiber-tracheids. |
|
|
Term
|
Definition
| Crowded pits in diagonal rows. |
|
|
Term
|
Definition
| Is the intergradation between libriform fiber and tracheid. Has bordered pits with cavities smaller than those in tracheids or vessels. Act as support and storage of reserve materials when they turn into septate fibers. |
|
|
Term
|
Definition
| Act in food storage and translocation of various substances radially. |
|
|
Term
|
Definition
| Circular or Oval pits in horizontal pairs or short horizontal rows. |
|
|
Term
|
Definition
| The pores in the sieve element walls. Pores vary in size even on different walls of a same cell. Usually the largest pores occur on the end of the sieve plates. |
|
|
Term
|
Definition
| Sieve plates on the end walls connect sieve tube elements into a longitudinal series forming sieve tubes. |
|
|
Term
|
Definition
| When sieve elements are dormant or die sieve pores are sealed by callose. Callose accumulates to restrict the interconnection through the pore as the sieve element ages. Respond to stress such as the spread of pathogens. |
|
|
Term
|
Definition
| Less specialized. Do not have sieve plates. |
|
|
Term
|
Definition
| Carry out all of the cellular functions of the neighboring sieve tube elements. |
|
|
Term
|
Definition
| Have sieve plates which allow for a higher degree of specialization for longitudinal conduction than sieve cells. Many sieve tube elements form a sieve tube. Lack a nucleus, ribosomes, and a vacoule, but these are stored in the neighboring companion cells. |
|
|
Term
|
Definition
| Have multiple sieve areas in a sieve plate. |
|
|
Term
|
Definition
| 2 types of sieve elements: sieve cells and sieve tube elements. Sieve elements are interconnected by pores, have highly modified protoplasts, have restricted metabolic activities and have thick walls with cellulose and pectin but no lignin. |
|
|
Term
|
Definition
| Highly specialized sieve areas on the end walls that provide a more complete interconnection between the sieve tube elements due to their larger pores. Have less sieve areas. |
|
|
Term
|
Definition
| The first part of the primary xylem to develop. Can be found towards the center of the stem or root. Usually become stretched or destroyed with age in shoots. Can form collapsed protoxylem. |
|
|
Term
|
Definition
| Form the latest after the maturation of the metaxylem. Act as the primary transport cells in most plants. |
|
|
Term
|
Definition
| The primary xylem formed later. Matures after the elongation of the surrounding tissues is completed. Usually contain intact tracheary elements, fibers and parenchyma cells. Remain functional until secondary growth. |
|
|
Term
|
Definition
| Found in metaxylem and secondary xylem due to the fact that they do not allow much elongation after maturation. |
|
|
Term
|
Definition
| Matures when the plant is elongating. Fibers occur on the periphery of the phloem. The sieve elements of the protophloem later become nonfunctional and than they may be obliterated. |
|
|
Term
|
Definition
| Matures when the primary growth is completed. Have large more distinct sieve elements. Functions longer than protophloem and are the only conducting phloem in plants without secondary growth. |
|
|
Term
|
Definition
| Occur in the tracheary elements. Occur after annular thickenings occur. Allow elongation after maturation. Can be found in the metaxylem. |
|
|
Term
|
Definition
| Occur in metaxylem and secondary xylem due to the fact that they do not allow much elongation after maturation. Succeeded by Reticulate Thickenings. |
|
|
Term
|
Definition
| Secondary walls may occur as rings in the earliest tracheary elements. Allow elongation after maturation. |
|
|
Term
|
Definition
| Are located throughout the plant body. Do not contain ray parenchyma. Contains protoxylem and metaxylem. Collapse after secondary xylem form. |
|
|
Term
|
Definition
| Forms during secondary growth from the vascular cambium. First produces small cells. |
|
|
