530 likes | 807 Vues
Plant structure - cells, tissue, organisation & growth Leaves and photosynthesis C 4 photosynthesis CAM photosynthesis Plant water relations Plants and nutrients Plant reproduction - asexual - sexual reproduction - pollination - seed dispersal. Shoot system. Root system.
E N D
Plant structure - cells, tissue,organisation & growth Leaves and photosynthesis C4 photosynthesis CAM photosynthesis Plant water relations Plants and nutrients Plant reproduction - asexual - sexual reproduction - pollination - seed dispersal
Shoot system Root system
Shoot system Lateral roots Root system Taproot
Shoot system Leaves Stem Lateral roots Root system Taproot
Shoot system Branch Leaves Stem Lateral roots Root system Taproot
Apical bud Lateral bud Shoot system Branch Leaves Stem Lateral roots Root system Taproot
Apical bud Node Lateral bud Internode Node Shoot system Branch Leaves Stem Lateral roots Root system Taproot
Basic functions of roots, stems and leaves:
Roots • Roots: • Find and absorb water • Find and absorb nutrients • Host symbionts • Anchorage and support • Attachment • Photosynthesis • Storage • Breathing or ventilation (mangroves) • Reproduction
Roots of pea plant Nodules Host symbionts
Leaves • Intercept light • Fix CO2 • Storage • Food • Water • Support • Protection (spines) • Collect nutrients • Animals • Leaves and compost • Reproduction • Asexual • Sexual (pollination)
Sunlight Shoot system CO2 Transport of water, sugar, and nutrients through vascular tissue Root system Water Nutrients (such as N, P, K)
Plant structure • - cells, tissue, organisation & growth • Leaves and photosynthesis • C4 photosynthesis • CAM photosynthesis • Plant water relations • Plants and nutrients • Plant reproduction • asexual • sexual reproduction • - pollination • - seed dispersal
Growth Determinate growth
Growth Determinate growth Indeterminate growth
Growth Determinate growth Indeterminate growth
Growth Determinate growth Indeterminate growth
(a) Longitudinal section of root segment Primary Growth Lateral root Zone of Cellular Maturation Root hair (b) Close-up of root tip Vascular tissue Zone of Cellular Elongation Ground tissue Epidermal tissue Zone of Cellular Division Apical mersitem Sloughed-off root cap cells mucilage Root cap
Primary Growth Leaf primordia Apical meristem at tip of shoot Apical meristem in lateral bud
Secondary Growth Cross section of a eudicot stem Epidermis Cortex Pith (ground tissue) Vascular bundle
Detailed view of vascular bundle in a eudicot Epidermis Collenchyma Phloem Cambium Xylem
Secondary meristem = cambium Cylinders the length of root or stem
Secondary meristem = cambium Cylinders the length of root or stem Increase width of stems and roots
Woody stems contain two lateral meristems. Vascular cambium adds cells on inside and outside
Woody stems contain two lateral meristems. Vascular cambium adds cells on inside and outside Cork cambium adds cells to the outside
Wood and bark contain a variety of cells and tissues. Cork Cork cambium Bark Secondary phloem Vascular cambium Wood Parenchyma cells (in rays) Secondary xylem
Secondary phloem Differentiation Division Differentiation Division Differentiation Vascular cambium Division Growth Secondary xylem Time
Heartwood and sapwood have different functions. Heartwood provides structural support but no longer transports water Sapwood transports water Bark
Growth rings result from variation in cell size. Late wood One growth ring Early wood
Core samples from three nearby trees These samples are lined up by year; notice similar ring patterns in trees from the same area