9.2 Transport in angiosperms

STARTER: What’s happenning here?

Past Paper Question (a)apical and lateral (b)2 max StructureMonocotyledonousDicotyledonus leafparallel veinsbranched (net of) veins; seedone cotyledontwo cotyledons; flowerfloral parts in multiple of 3floral parts in multiple of 4 or 5; stemscattered vascular bundlesring of vascular bundles around central pith; rootadventitious rootsbranched tap roots; Award [1] for each correct line (c)auxin produced at apical meristem / tip; transported to growing area / zone of cell growth; lateral transport to cells on shade side; results in cell expansion; shoot “grows” towards light source; experimental detail;3 max

Learning Objectives List ways in which mineral ions in the soil move to the root. Explain the process of mineral ion absorption from the soil into roots by active transport. Outline four adaptations of xerophytes that help to reduce transpiration. Outline the role of phloem in active translocation of sugars (sucrose) and amino acids from source (photosynthetic tissue and storage organs) to sink (fruits, seeds, roots).

Extended Response Practice Outline the movement of water in plants from root to leaf, including the effects of abiotic factors on the rate of transport. (6) transport: [3 max] water transported in xylem vessels; transpiration pull; due to loss of water vapour from leaves (and stems) / evaporation of water from leaves; cohesion of water molecules (due to hydrogen bonds) / continuous column of water; capillarity / adhesion; transpiration stream is flow of water within the plant; transpiration stream is flow of water from roots through the plant; abiotic factors: [3 max] (accept inverse statements) light: in day guard cells are open so increases evaporation and transport of water; temperature: higher temperatures increase evaporation and transport of water; wind: more wind, faster evaporation and increase transport; humidity: higher humidity in air decreases (rate of transpiration) and transport; CO2 concentration: if high, stomata close and lower transpiration rate;6 max