BIOL 1002 Chapter : Ch 45 Plant Responses To The Environment
Document Summary
Plants sense and respond to different stimuli in their environment through the action of chemicals called plant hormones or growth regulators. Hormones are vital to plant growth: what are the stimuli that plants receive from their environment? touch gravity, moissture light, day length (night length) The bending of plants towards sunlight, phototropism(tropism-growth: discovery of plant hormones: the darwins-charles and his son. The tip transmits info about direction of light further down to bending region of stem (fig e45- 2,3: how does the plant bend, one side gets longer than the other, peter boyson-jensen discovered that the signal that causes the bending is a chemical. E45-4 produced in tip and moves down shoot to cause cell elongation. Frits went isolated that chemical compound and called it auxin- to increase tips placed in agar: he then took agar that collected the auxin and placed it on stumps to see the effects: fig.
