Seed Plant embryo seed coat Seed offers endosperm

Seed & Plant embryo seed coat § Seed offers… endosperm protection for (3 n) embryo u stored nutrients cotyledons for growth of embryo u embryo (2 n) cotyledon = “seed” leaf, first leaves of new plant AP Biology

Monocots & dicots § Angiosperm are divide into 2 classes u dicots (eudicot) § 2 cotyledons (seed leaves) § leaves with network of veins § woody plants, trees, shrubs, beans u monocots § 1 cotyledon § leaves with parallel veins § grasses, palms, lilies AP Biology

AP Biology

Transport in Plants AP Biology 2006 -2007

Epidermal cell Guard cell Control of Stomates H 2 O K+ Nucleus Chloroplasts H 2 O K+ K+ H 2 O Thickened inner cell wall (rigid) H 2 O K+ AP Biology H 2 O K+ Stoma open Stoma closed water moves into guard cells water moves out of guard cells

4 Transport in plants 3 5 2 6 AP Biology 1 7

Ascent of xylem fluid Transpiration pull generated by leaf AP Biology

Water & mineral absorption § Water absorption from soil osmosis u aquaporins § Mineral absorption u active transport u proton pumps u § active transport of H+ AP Biology proton pumps aquaporin

Mineral absorption § Proton pumps u active transport of H+ ions out of cell § chemiosmosis § H+ gradient u creates membrane potential § difference in charge § drives cation uptake u creates gradient § cotransport of other solutes against their gradient AP Biology

Water flow through root § Symplast plasmodesmata § Apoplast u Casparian strip AP Biology

Controlling the route of water in root § Endodermis cell layer surrounding vascular cylinder of root u lined with impermeable Casparian strip u forces fluid through cell membrane u AP Biology

AP Biology

Transport of sugars in phloem § Translocation §flow through cells via plasmodesmata u AP Biology proton pumps § cotransport of sucrose into cells down proton gradient

Pressure flow in phloem § Bulk flow “source to sink” u increased [sucrose] decreases H 2 O potential u water flows in from xylem u u ↑in pressure due to ↑ in H 2 O causes flow AP Biology can flow 1 m/hr

Maple Sugaring AP Biology