2.81 Phototropism

KEY POINTS
 Growth in response to light and the positive suggest towards the light



The stem grow towards the light =positive
away from the light = negative 


The plants bends to the lateral light causes the opposit side of a compoud ( austin : plants hormones) causes more growth than the other side = Bend

2.80 Geotropism

Key Points
 Geotropism = growth responses togravity



Example of a seed:


Embrionic root ->grows downwards = positive geotropisim


Embrionic shoot->grows upwards to the surface = negative geotropism


Rotate it to sideways 
The shoot grows upwards= negative
root-> Grows down =positive

2.79 Plants and stimuli

KEY POINTS

1.stimuli are changes in the environment eg. temperature, light


2.Plants have receptor which detect stimuli


3.This turns into response - Growth
(Tropism)


4.Tropism involvle light which involve phototropism and geotropism ( gravity)


5.Connection between receptor and response usually takes the form plants hormones

2.54 Transpiration

5 Key points

1. transpiration will occur where H20 liquid change into Gas
2. This is created by the sunlight where light energy transfer to heat and absorb by the structure of the leaf
3. Water from the roots travel to the leaf by the osmosis
4. Heat from the sunlight causes the water to become a vapour where it is 100% humidity in leaf spaces
5. The phase change occured and the gas diffuses out of the leaf through the stomatl pore by the steep diffusion gradient and also to the lower humidity outside

Diagram of a root

2.53 Roots structure