2.81 Phototropism

-Phototropism is the growth response to light

-As it is positive, the growth is upward, towards the light

-Wherever the light comes from, the plant leans towards, for example if the light is coming

from the side, the plant will bends toward the light

-This is caused my the plant hormones

2.80 Geotropism

-Geotropism is the growth response to gravity

-When the root grows downwards, it is called positive geotropism

-When the root grows upwards, it is called negative geotropism

2.79 Plants and stimuli

-Stimuli are changes in the environment

-Plants have receptors which detect the stimuli and turn those into a response

-The responses often take the form of growth

-There are different types of tropisms (growth from stimuli)

-A tropism involving a response to light is called a phototropism and a response to gravity is called a geotropism

-The connection between the receptor and the response is plant hormones

2.54 Transpiration

-Evaporation changes from the liquid phase to the gas phase, the heat is provided by the sunlight as the structure of the leaf absorbs the light

-Evaporation occurs through the stomatal pores

-Not all of the light is absorbed through chloroplast, absorbed through other cell structure and thus generates heat.

-In the spongy layer, there is a phase change

-The water vapor diffuses down the diffusion gradient and then through the stomatal pore

2.53 Root uptake of water

-Root branches out, creating larger surface area for absorption

-Cell wall extends, thus creating more surface area for more intake of water

-At the bottom of 'root hair' active transport of minerals into the xylem

-Where outside is dilute, and inside the cell is concentrated with minerals, osmosis occurs

-Increase of minerals in cell through active transport increase the concentration which allows osmosis to take place