Root Structure and Function - Biology of Plants - Lecture Slides, Slides of Biology

Download Root Structure and Function - Biology of Plants - Lecture Slides and more Slides Biology in PDF only on Docsity! Root Structure and Function Penetration of Soil Gravitropism Downward Growth Water and Mineral Intake Conduction (Xylem and Phloem) Storage of Materials Branching Anchorage Docsity.com Notice how the growing zone has no root hairs or lateral roots! Growth among soil particles would result in shear forces. Zone of Maturation - cell differentiation Protoderm Ground Meristem Provascular Zone of Cell Elongation - cell expansion Zone of Cell Division - new cells by mitosis Root Cap - penetration, padding Docsity.com © 19 96 N or to n Pr es en ta tio n M ak er , W . W . N or to n & C om pa ny Radish seedlings have roots with long root hairs that increase the surface area for water and mineral uptake Docsity.com Osmosis: passive movement of water from pure to polluted area cytoplasmic solutes more concentrated soil solutes more dilute cell membrane Water potential low Water potential high cell wall water flow Docsity.com Root hairs are responsible for cation exchange soil particles covered with capillary water and minerals water voids with air space root hair penetrates soil spaces epidermal cell cortex cell H+ Ca2+ H+ Ca2+ Ca2+ intercellular gas space to vascular cylinder Docsity.com Root Vascular Cylinder and Cortex Ranunculus acris - buttercup Cortex Endodermis Meta- xylem Phloem Pericycle Proto-xylem Endarch: protoxylem is inside the metaxylem Exarch: protoxylem is outside the metaxylem √ Docsity.com haplostele siphonostele eustele solenostele dictyostele atactostele leaf gap leaf trace cortex phloem xylem cortex phloem xylem pith dicot stem monocot stem Protosteles: actinostele plectostele Specialized Versions dicot root monocot root Docsity.com © 19 96 N or to n Pr es en ta tio n M ak er , W . W . N or to n & C om pa ny Apoplastic Symplastic Docsity.com Root Anatomy: Dicot Root Cross Section Epidermis - root hairs, mineral and water intake Cortex - storage, defense Endodermis - selective mineral uptake Pericycle - lateral root formation (periderm) (Vascular Cambium - makes 2° tissues) Phloem - CH2O delivery from leaves Xylem - conduct water and mineral upwards Casparian strips in radial walls One Vascular Cylinder (Phloem + (Cambium) + Xylem) Radial Xylem-Phloem Arrangement Exarch Xylem Maturation Tetrarch (this example) Docsity.com Monocot Root Cross Section Smilax-catbrier Pith Xylem/Phloem Arr? Xylem Maturation? ______arch? Docsity.com How is this section different? Smilax - catbrier Docsity.com