Download Plant Structure Growth and Development - Lecture Notes | BIOL 1202 and more Study notes Biology in PDF only on Docsity! Chapter 35: Plant Structure, Growth, and Development Concept 35.1: The plant body has a hierarchy of organs, tissues and cells The Three Basic Plant Organs Plants draw nutrients from 2 very different environments: below ground and above ground 3 basic organs: o Roots o Stems o Leaves Organized into the root and shoot system Figure 35.2 **Roots are involved in all but which of the following activities? 1. Support 2. Food storage 3. Food production 4. Anchorage Roots An organ that anchors the vascular plant Absorbs minerals & water o Absorption occurs near root tips o Root hairs increase the surface area of the root Stores organic nutrients Stems Consits of: o Nodes- points at which leaves are attached o Internodes- segment between nodes o Axillary buds- potential to form lateral shoot (i.e., branch) o Terminal bud- located at shoot tip, causes elongation of a young shoot Leaves The leaf is the main photosynthetic organ of most vascular plants Consist of: o A flattened blade o The petiole, which joins the leaf to a node of the stem o Figure 35.2 Simple vs. Compound Leaves o Simple leaf: a single, undivided blade Some may have deep lobes o Compound leaf: blade consists of multiple leaflets o Doubly compound leaf: each leaflet is divided into small leaflets o Figure 35.6 The Three Tissue Systems: Dermal, Vascular, and Ground Dermal: consists of the epidermis and periderm Vascular: Carries out transport of materials between roots and shoots o Xylem: conveys water and minerals up from roots o Phloem: transports organic nutrients from sources to sinks Ground tissue: various functions including storage, photosynthesis and support o Figure 35.8 Differentiated Plant Cells Parenchyma o Thin flexible 1° cell walls; alive at maturity; carry out most metabolism within a plant Collenchyma o Unevenly thickened, but flexible 1° cell walls; alive at maturity; supports young growing stems Sclerenchyma o Thick, rigid 2° cell walls; dead at maturity; provides support o Figure 35.10 Xylem o Conducts water and minerals from roots Tubular cells; dead at maturity Trachids: thin, tubular cells; cell walls contain pits (thin regions with only 1° cell walls) Vessel elements: short, wide tubular cells Phoelm o Conducts organic compounds Sieve-tube members: conducting cells; alive, but not many organelles Companion cells: nonconducting cells; alive and supports sieve-tube members o Figure 31.10 **Unlike collenchymas and sclerenchyma tissues, parenchyma tissue does not function in.. 1. Support 2. Gas exchange 3. Nutrient exchange 4. Both gas exchange and nutrient exchange **A typical eudicot leaf is composed of.. 1. A node and an internode 2. A terminal bud 3. A blade and a petiole 4. Parallel veins
