Other Elements
Extra information about processes related to plant water balance.
Transpiration
Transpiration is the process by which water is lost by the plant. Transpiration occurs all he time, however some plants like xerophytes for example have adaptations in place so that transpiration does not occur so regularly.
"Transpiration assists the plant by: a.) being the main cause of the movement of water from the roots to the leaves (transpiration pull) and
b.) keeping the plant cool in hot weather, as water draws heat from leaves to vaporise."1
The transpiration pull is where the water is pulled from the roots to the leaves via the xylem vessels. Transpiration is assisted by adhesion in the xylem vessels; adhesion being the water molecules being attracted to the walls. Transpiration or the water evaporating from the leaves can also be assisted by cohesion which is the water molecules being attracted to each other. On one side of a water molecule it is slightly more positive and on the other side it is slightly more negative. This means that the positive side of one water molecule is attracted to the negative side of another and so it forms a train of molecules evaporating out from the leaf.
"Transpiration assists the plant by: a.) being the main cause of the movement of water from the roots to the leaves (transpiration pull) and
b.) keeping the plant cool in hot weather, as water draws heat from leaves to vaporise."1
The transpiration pull is where the water is pulled from the roots to the leaves via the xylem vessels. Transpiration is assisted by adhesion in the xylem vessels; adhesion being the water molecules being attracted to the walls. Transpiration or the water evaporating from the leaves can also be assisted by cohesion which is the water molecules being attracted to each other. On one side of a water molecule it is slightly more positive and on the other side it is slightly more negative. This means that the positive side of one water molecule is attracted to the negative side of another and so it forms a train of molecules evaporating out from the leaf.
Photosynthesis
Photosynthesis is where plants convert carbon dioxide and water into glucose. It is a chemical process that requires water, so therefore can be reduced in some plants so that water usage is also reduced. Nevertheless it is an important process as the glucose made from it is then used to make energy for which the plant can use to grow the roots deeper or curl up its leaves tighter etc.
Types of Adaptations
Structural: "The physical features of an organism that help it to survive and succeed in tis environment"2
Behavioural: "Behavioural adaptations are the things organisms do to survive."3
Physiological: "The adjustment of an organism to its environment."4
Behavioural: "Behavioural adaptations are the things organisms do to survive."3
Physiological: "The adjustment of an organism to its environment."4
References:
1. ESA Level 2 Biology workbook chapter 26, page 255.
2. http://www.ask.com/science/structural-adaptation-3d379432c1eddff2
3. http://www.nhptv.org/natureworks/nwep1.htm
4. http://medical-dictionary.thefreedictionary.com/Physiological+adaptations
1. ESA Level 2 Biology workbook chapter 26, page 255.
2. http://www.ask.com/science/structural-adaptation-3d379432c1eddff2
3. http://www.nhptv.org/natureworks/nwep1.htm
4. http://medical-dictionary.thefreedictionary.com/Physiological+adaptations