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
Taproot Lateral roots Shoot system Root system
Taproot Lateral roots Leaves Stem Shoot system Root system
Taproot Lateral roots Branch Leaves Stem Shoot system Root system
Taproot Lateral roots Apical bud Branch Leaves Stem Shoot system Root system Lateral bud
Taproot Lateral roots Apical bud Branch Node Internode Leaves Lateral bud Stem Node Shoot system Root system
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
Absorbing water and nutrients
Host symbionts Roots of pea plant Nodules
Anchorage and support
Attachment
Photosynthesis!
Storage
pneumatophores
Asexual reproduction
Stems
Transport and support.
Cactus stems store water, photosynthesize.
Stolons produce new individuals at nodes above ground.
Rhizomes produce new individuals at nodes below ground.
Tubers store carbohydrates.
Thorns provide protection.
Leaves Intercept light Fix CO 2 Storage Food Water Support Protection (spines) Collect nutrients Animals Leaves and compost Reproduction Asexual Sexual (pollination)
Transport of water, sugar, and nutrients through vascular tissue CO 2 Sunlight Water Nutrients (such as N, P, K) Shoot system Root system
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
Growth Determinate growth
Growth Determinate growth Indeterminate growth
Growth Determinate growth Indeterminate growth
Growth Determinate growth Indeterminate growth
Vascular tissue (b) Close-up of root tip Ground tissue Epidermal tissue Apical mersitem Sloughed-off root cap cells Root cap Root hair Zone of Cellular Maturation Zone of Cellular Elongation Zone of Cellular Division Lateral root (a) Longitudinal section of root segment mucilage Primary Growth
Leaf primordia Apical meristem at tip of shoot Apical meristem in lateral bud Primary Growth
Primary growth
Cross section of a eudicot stem Epidermis Cortex Pith (ground tissue) Vascular bundle Secondary Growth
Detailed view of vascular bundle in a eudicot Epidermis Collenchyma Phloem Xylem Cambium
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
Vascular cambium adds cells on inside and outside Woody stems contain two lateral meristems.
Cork cambium adds cells to the outside Vascular cambium adds cells on inside and outside Woody stems contain two lateral meristems.
Wood and bark contain a variety of cells and tissues. Secondary phloem Bark Wood Parenchyma cells (in rays) Vascular cambium Cork cambium Cork Secondary xylem
Growth Division Differentiation Division Differentiation Division Differentiation Time Secondary phloem Vascular cambium Secondary xylem
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. One growth ring Early wood Late wood
Increment borer cuts core from trunk.
Core samples from three nearby trees These samples are lined up by year; notice similar ring patterns in trees from the same area