LECTURE 19- Hormone: regulators of development I

what happens when you shine light on one side of a monocot coleoptile

it will bend towards the light

where does cell elongation take place

in the middle of the coleoptile: that’s where light signals are found

where in the plant are the light receptors found

at the very tip of the coleoptile

what does it mean if the plant tip has light receptors, but bends in the middle

it means the signal has to travel downwards, and the signal travelling is involved with chemistry (hormones) (DNA or plant organs don’t travel)

where does auxin have a higher concentration

auxin has higher concentration on the cells further from the light, than the cells closer to the light

• auxin is chemically different on each side of the coleoptile

which side does auxin travel down the coleoptile

auxin travels down the side away from the light

• a chemical on the outside of the plant (auxin) is what’s causing cell elongation

what happened to the plant when an agar plug was placed on the left side of the coleoptile

coleoptile will bend towards the right

• shows that the outer edge has the bending chemical