tailieunhanh - Lecture Biology: Chapter 35 - Niel Campbell, Jane Reece
Chapter 35 - Plant structure, growth, and development. This chapter compare structures or cells; explain the phenomenon of apical dominance; distinguish between determinate and indeterminate growth; describe in detail the primary and secondary growth of the tissues of roots and shoots; describe the composition of wood and bark; distinguish between morphogenesis, differentiation, and growth; explain how a vegetative shoot tip changes into a floral meristem. | Chapter 35 Plant Structure, Growth, and Development Overview: Plastic Plants? The fanwort plant exhibits developmental plasticity, the ability to alter itself in response to its environment. Developmental plasticity is more marked in plants than in animals. In addition to plasticity, plant species have by natural selection accumulated characteristics of morphology = form that vary little within the species. The fanwort has two types of leaves -- developmental plasticity Figure Why does this plant have two types of leaves? Concept : The plant body has a hierarchy of organs, tissues, and cells Like multicellular animals, plants have organs composed of different tissues, which in turn are composed of cells. Three basic organs evolved: roots, stems, and leaves. They are organized into a root system and a shoot system: Roots rely on sugar produced by photosynthesis in the shoot system. Shoots rely on water and minerals absorbed by the root system. Flowering Plant Morphology Reproductive shoot (flower) Apical bud Node Internode Apical bud Shoot system Vegetative shoot Leaf Blade Petiole Axillary bud Stem Taproot Lateral branch roots Root system Figure An overview of a flowering plant The Three Basic Plant Organs: Roots, Stems, and Leaves Roots are multicellular organs with important functions: Anchoring the plant Absorbing minerals and water Storing organic nutrients A taproot system consists of one main vertical root that gives rise to some large lateral roots, or branch roots. Adventitious roots arise from stems or leaves. Seedless vascular plants and monocots have a fibrous root system characterized by many thin lateral roots with no main root. In most plants, absorption of water and minerals occurs near the root hairs, where vast numbers of tiny root hairs increase the surface area. Root Hairs of a radish seedling Figure Root hairs of a radish seedling Many plants have modified roots Prop roots “Strangling” aerial roots Storage roots Buttress roots | Chapter 35 Plant Structure, Growth, and Development Overview: Plastic Plants? The fanwort plant exhibits developmental plasticity, the ability to alter itself in response to its environment. Developmental plasticity is more marked in plants than in animals. In addition to plasticity, plant species have by natural selection accumulated characteristics of morphology = form that vary little within the species. The fanwort has two types of leaves -- developmental plasticity Figure Why does this plant have two types of leaves? Concept : The plant body has a hierarchy of organs, tissues, and cells Like multicellular animals, plants have organs composed of different tissues, which in turn are composed of cells. Three basic organs evolved: roots, stems, and leaves. They are organized into a root system and a shoot system: Roots rely on sugar produced by photosynthesis in the shoot system. Shoots rely on water and minerals absorbed by the root system. Flowering Plant Morphology .
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