Plant Hormones / Req Practical 8

Shoots grow up against gravity, in the roots auxins accumulate on the lower side of the root encouraging growth downwards Use clinostate, a device that continually rotates, this cancels out the effect of gravity, the shoots continue growing the way they were originally growing As control set up a normal experiment without clinostate so the gravity force is still present, place 3 seedlings in a pot and leave for the same time u left the other leaves (1week). Shoots grow up (positive phototropism/ negative gravitropism) Roots grow down (negative phototropism / positive gravitropism)

Add 10 seedlings to 3 separate cotton wool pads, place 1 in box with cut out on left, one with cutout on right, one with cutout on top. Leave for 1week and measure how the seedlings curve (they curve towards light source as they’re positively phototropic. Controls: Seedling type / Amount of water Independent : direction of light Dependant : mean curve of seedlings towards light source

Add 10 seedlings to 3 separate cotton wool pads, place 1 in bright light, one in reduced light, one in the dark. Leave for 1week and measure how much the seedlings grow by (mean). They grew the fastest in the dark as they grow rapidly in order to grow out of the ground Controls: Seedling type / Amount of water Independent : light intensity Dependant : mean height of seedlings

Coordinate + control growth / responses to light (phototropism) / gravity (gravitropism)

Cause growth in roots and shoots Weed killers / rooting powder / promoting growth in tissue culture

Initiating seed germination Promotes flowering / end seed dormancy / increase fruit size

Control cell division + cell ripening Fruit industry = control ripening of fruit during transportation / storage