Plant anatomy

• During osmosis, water travels from areas of low solute concentration, to areas high solute concentration
• Tropisms: are changes a plants growth in response to a stimulus (occurring slowly)
• Gravitropism (Geotropism):

  • positive: growing in direction of gravity (Ex. plant root will always grown downward)
  • negative: growing against gravity (Ex. plant shoot)
• Phototropism: plants response to light (positive, growing toward & negative away)
• Thigmotropism: response to touch & pressure
• Chemotropism: response to chemicals (Ex. roots are positive when they look for minerals and negative for acids)
• Hydrotropism: response to water
• Nastic movements (turgor responses): quick, reversible movements that don't depend on orientation (Ex. snap of Venus fly trap)
• Plant hormones: control most tropisms and growth in plants.

  • some are inhibitors and promotors
• Auxins: A plant hormone that promotes the growth of shoots and roots, as well as leaf cycling
• Gibberellin: Promote germination of seeds and elongation of stem cells.
• Cytokinins: promote cell division & differentiation & delay leave aging