SYSTEMS IN PLANTS 4.1 Plants are multicellular organisms with two obvious distinguishing features: They are usually green They cannot move from place to place. Flowering plants have two main “body systems:” the root system and the shoot system. These two body systems work together to perform all of the functions necessary to keep the plant alive: exchanging gases with its surroundings moving water and nutrients around internally reproducing

Hierarchy of Organization The plant has 2 main body systems and three main types of plant tissue systems. Dermal tissue system – tissues that cover outer surface of the plant Vascular tissue system – tissues responsible for transporting materials within the plant Ground tissue system – all other plant tissues

The Systems The root system is typically the part of the plant that grows underground. Its functions are to anchor the plant, to absorb water and minerals from the soil, and to store food. The shoot system of flowering plants is made up of three parts: the leaf, the flower, and the stem. The Leaf The leaf is where photosynthesis takes place. Chloroplasts in a plant’s leaves use carbon dioxide, water, and light energy to produce glucose and oxygen. light energy + carbon dioxide + water glucose + oxygen chlorophyll

4.1 2. The Flower Flowers contain male or female reproductive structures. Male reproductive structures produce pollen grains. Female structures produce eggs. After eggs are fertilized by pollen, seeds form within a specialized structure called a fruit. 3. The Stem A plant’s stem supports the plant’s leaves and flowers, and provides a way to transport the materials the plant needs. Uses: People use flowering plant roots, leaves, stems, and flowers (plus the seeds and fruits that come from them) for food, flavourings, fibres, and medicines.

PLANT TISSUE SYSTEMS 4.2 Similar to stem cells in animals, meristematic cells are undifferentiated plant cells that can form any kind of specialized tissue. Plant tissues are classified into three tissue systems, each containing a variety of specialized cell types that carry out specific functions within the plant. The three major tissue systems of plants are dermal vascular ground

PLANT TISSUE SYSTEMS 4.2 The dermal tissue system forms the outmost layer of a plant. It includes both epidermal and peridermal tissues. These tissues are what you see when you look at the leaves, stem, and roots of a plant. Epidermal tissue (epidermis) is the thin layer of cells that covers the surfaces of leaves, stems, and roots. In woody plants, the epidermal tissue is replaced by periderm tissue, which forms bark on stems and large roots. Some cells of the dermal tissue system absorb water and minerals from the surrounding soil. Others produce a layer of wax to waterproof the surface of leaves. Still others contain chemical irritants for defence. A plant’s vascular tissue system is like a network of tubes that reaches from the roots up the stalk to the leaves. When a plant’s roots absorb water and nutrients from the soil, the vascular tissue system transports the water and nutrients to the various parts of the plant, where they are needed for growth. epidermal tissue (epidermis) periderm tissue

PLANT TISSUE SYSTEMS 4.2 There are two types of vascular tissue: xylem and phloem. Xylem carries water and dissolved minerals from the roots to the rest of the plant. Water moves through the tubes in one direction. Phloem transports solutions of sugars produced during photosynthesis, as well as other dissolved nutrients and hormones. In phloem tissue food materials may be transported in either direction: downward from photosynthesizing leaves to stem and roots or upward from the root and stem to the leaves. xylem phloem

Xylem Xylem is a term applied to woody walls of certain cells of plants. Xylem cells tend to conduct water and minerals from roots to leaves. Phloem cells conduct food from leaves to rest of the plant. They are alive at maturity and tend to stain green (with the stain fast green). Phloem cells are usually located outside the xylem. Cambium in plants is a layer of actively dividing cells between xylem and phloem tissues that is responsible for the secondary growth of stems and roots

Ground tissue cells are part of the third major tissue of plants Ground tissue cells are part of the third major tissue of plants. They are the filler between the dermal and the vascular tissues. Ground tissues perform a variety of functions, depending on their location within the plant: In the green parts of the plants, they manufacture nutrients by photosynthesis. In the stems, they provide storage and support. In the roots, they store carbohydrates

Leaves Dermal ground Vascular All three of these tissues come together in the leaf of a plant. Label Leaf diagram ground Vascular