Transcript
Page 1: Coordination in Plants...Coordination in Plants y using their hormones or ohormones tal changes Movement in Plants Geotropism Chemotropism Hydrotropism Thigmotropism Ex. Mimosa leaf,

Coordination in PlantsPlants coordinate their behaviour by using their hormones or phytohormonesand respond to the environmental changes

Movement in Plants

Geotropism

Chemotropism

Hydrotropism

Thigmotropism

Ex. Mimosa leaf, Venus Flytrap

ThigmonastyThigmonasty is the response of

a plant to touch or vibration

Ex. Sunflower, Dandelion flower

PhotonastyMovement of plant parts in

response to light

Movement of plants in response to chemicals

Ex: The growth of pollen tube towards the ovule during fertilization in a flower

Pollen

Ovule

Pollen tube

Sperm nuclei

Stigma

Movement of plants in response to water

Ex: Roots of a plant move towards water

Directional movement of plants in response to the touch of an object

Ex: Tendrils of a climber plant climb towards any support which they can cling upon

PhototropismMovement of plants in response to light

Ex. The shoot of the plant moves towards the light

Movement of plants in response to gravity

Positive Geotropism Roots of a plant move in a downward direction

Negative geotropism Stem moves in the upward direction

Tropic Movements Growth dependent

(towards or away from a stimulus) (independent of stimulus's position)

Nastic MovementsGrowth independent

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