photo of phototropism

2.55 rate of transpiration

- transpiration is the loss of water through the leaf causd by the evaporation which the water has to be changed from liquid to gas which diffuses through the stomatal pore
- if the concentration gradient of water has a big difference then it has a high rate of transpiration. if the difference is small then it would be a low rate of transpiration
- the factors that would cause a large difference would be- low humidity, high winds, high temperature and high light intensity. This will result in fast diffusion from inside to outside of the leaf
- the rate of transpiration depends on the factors of humidity, wind, temperature and light intensity

2.81 phototropism

http://www.youtube.com/watch?v=tE4XMg4Y_d4

- photptroism is the growth with light
- positive phototropism isthe growth towards the light
- when the stem is hit by light rays the stem will grow up
- if the light is lateral, then the stem tip will grow to its side, this is an example of positive phototropism
- auxin is a hormon which causes cell division and then causes the cell to grow up, when the light rays hit the stem it causes the auxin to move to one side (the side which the light does not hit) and therefore bending it because its only growing on one side 

2.80 geotropism

http://www.youtube.com/watch?v=76AWJiVJR1E

- geotropic is the gravity of growth response
- the roots of a seed grow down which is positive geotropism, the shoots of the seed grow up which is negative tropism
- if the seed is turned to its side then the roots will still grow positive tropism, and the shoots negative tropism

2.79 plants and stimuli

http://www.youtube.com/watch?v=GxFF7BaVyQI

- stimuli are changes in the environment- light or temperature
- receptors detect the stimuli and then turns it into a response
- responses often take the form of growth- this is called a tropism, tropism that involves light is called phototropism
- tropism that involves gravity is called geotropism
- the connection that involves the receptor to the response is called plant hormones

2.54 transpiration

http://www.youtube.com/watch?v=w0Y1llaghwc

- water turns from liquid to gas using heat from sunlight
- the evaporation is through the stomatal pores
- sunlight goes into the chloroplast for photosythesis, this will generate heat
- water is being delivered from the xylem, moves through the spongy layer
- just below the stomatal pore is where the liquid turns to gas
- water vapour diffuses into the outside atmostphere, which is a steep diffusion gradient 

2.53 root structure

- the branching pattern of roots increases the surface area which absoubtion
- the root hair is caused by the cell wall which is extended outwards
- there is an increase of surface area absorbtion of water
- the process of absorbtion: active transport of minerals from root
- plant takes up water
- water moves across coflex through the xylem
- this is the process of osmosis - dilute to concentrated