Plant Structure and Growth A. Flowering Plant Parts: The flowering plants or are the most diverse group of plants. They are divided into 2 classes and. Examples of monocots: Examples of dicots: The morphology of a plant body has a subterranean system and an aerial system. The 2 types of vascular tissue are which conducts water upward from the roots and which transports food made in the leaves throughout the plant. B. Plant Cells:
There are 3 types of ground plant cells:,, and cells that differ mostly by their. Parenchyma cells are the common plant cells. They have, primary cell walls. Their functions are for in the chloroplasts of the leaves of parenchyma cells, some of these cells are involved in (starch), and these cells carry out most of the plant s metabolic needs. Collenchyma cells have primary cell walls. These cells are grouped into like the strings of a stalk. Their function is to parts of the plant still growing. Sclerenchyma cells have the cell walls of all three cell types. At maturity, these cells are and cannot grow in length like the other cells. Their function is which is reinforced by a cell wall hardened with. These cells are found in things like. Ground Tissue Function Cell Types in This Tissue Parenchyma Tissue Photosynthesis Food storage Healing and tissue regeneration Parenchyma cells Collenchyma Tissue Support in young stems, roots, and petioles Sclerenchyma Tissue * Rigid support Protection Collenchyma cells Sclereid cells & fiber cells *Some texts include tracheids and vessels as components of sclerenchyma tissue. Q: Potatoes contain food in the form of starch, which ground tissue are you eating when you eat mashed potatoes? Q:. Which ground tissue is a major component of the blades of spinach leaves? Two other important cells are the cells that form the vascular tissues of the xylem and phloem. The xylem s function is to conduct water and minerals and provide. These cells have both a and cell wall for added strength. There are 2 types of xylem cells: and.
Tracheids are and thin, while vessel elements are wider and. Both tracheids and vessel elements are arranged in tubes laid end- to-end where water flows through the openings at their ends and through the holes in the cells called. The tubes are and the cells are. The phloem s function is to conduct sugars. The phloem is made up of cells laid end-toend called members. They have no cell walls and are at maturity. Pores on the end of these sieve-tube members form sieve -where sugars and ions move between the food-conducting cells. This allows the cytoplasm of one sieve-tube member to make contact with the next cell. Also, sieve tubes have cells next to each cell that are called cells. Companion cells are connected to the sieve-tube member by many -similar to junctions in animal cells. Companion cells make proteins for the sievetube member cells that lack and. And some companion cells help load made in the leaf into the sieve-tube member cells. Other plant cell types include the cells that cover the outside of the plant. This is generally a layer of tightly packed cells that protect the plant and form tissue. Some epidermis cells like those found on root
hairs are involved in absorption. While other epidermis cells like those on leaves secrete a waxy coating called the that helps the plant retain water. C. Seeds and Roots: Recall that a seed forms when an and come together in fertilization. The seed is the embryo, a seed coat, and some storage material like the and the. After a seed reaches maturity, it remains until environmental cues cause it to. Cues includes,, light, opening of the seed coat. is the most important cue to activate various inside the seed which starts. Then the young root called the breaks out of the seed coat and anchors the seedling. In the young seedling, growth occurs at the tips of the roots and the shoots and is called. This is very active growth/cell divisions and called growth. Later, secondary growth occurs only in plants that thicken their roots and shoots. This leads to plants like conifers and woody dicots. The roots of dicots are that consist of one large vertical root and many smaller roots. This is a firm and helps plants tap water from far below ground. The roots of monocots are thread-like mats that spread out in the layers of soil. This helps to hold soil in place and prevent. In addition, on root tips increase the surface area of the root tremendously. Also recall that - fungi living on plant roots and in many plants, also absorb water and minerals as well. And in some plants, the roots rise ground to gain access to water and help support stems, these roots are. The structure of the roots can be divided into areas based on the cell activity. The root tip is protected by a thimble-like that protects the cells from the abrasive soil. The cap also secretes a slime to help push through the
soil. Up from the root cap is the zone of. These rapidly dividing cells absorb water and blend into the next region the zone of. Here the cells elongate to more than their original length. The last zone of the root is the zone of. Here the cells begin to into specialized functions such as mature into xylem or parenchyma cells. In addition, form extensions here. While we just described the regions of growth for the root, be aware that similar regions exist for the growth of the shoot (minus the root cap). D. Roots, Stems, and Leaf Cross-Sections: There are 3 tissue systems to the roots, stems and leaves. The, the tissue system in between, and the tissue system with the xylem and phloem. Look at the roots below. Recall the epidermis has root hairs in the zone of maturation to absorb water. The ground tissue system has the which stores and has lots of between the cells. And the ground tissue system has the in the innermost part of the cortex. The endodermis is a permeable barrier that determines what can enter into and out of the tissue. These cells especially control movement. Where the vascular cylinder, also called the includes the xylem and phloem. In addition, the stele of monocots have a central core of parenchyma cells called the. Look at the stems below. Primary tissue in the stem is similar to primary tissue in the roots. The epidermis however has a waxy cuticle and the cortex contains. Also, the vascular cylinders are different. In dicots, the stem s vascular bundles are in a around the outside of the stem. In monocots, the vascular bundles are throughout the ground tissue.
Look at the leaf below. Recall the epidermis of leaves is covered by a waxy cuticle. This reduces water loss or -evaporation of water from plants. The mesophyll cells have many where photosynthesis primarily occurs. The mesophyll cells are loosely packed and thus allow for exchange (O 2 and CO 2 ) to respiring cells. The cells on the epidermis control the opening and closing of. The vascular bundles consists of the normal xylem and phloem. But some plants like plants also have cells to provide an environment for the cycle to only fix.
E. Tree Cross Section: