Chapter 1 Water for living
1.1 Water is essential for living things
1 All living things require water for their life processes; without it they simply cannot exist.
2 A solvent is a liquid in which a solute is able to dissolve and make a solution, i.e. the solute is the substance that dissolves in a liquid or solvent to make a solution.
3 Living things use water to transport dissolved nutrients, gases and wastes around their bodies, and hydrate cells. Water is also an important reactant in many of the processes that take place in living things, e.g. photosynthesis in plants.
4 Animals obtain water by drinking it directly, extracting it from the food that is eaten or in some cases as a product from metabolic processes. Plants obtain water by absorption from the soil through the roots.
|Plants |Animals |
|Leaf rolling to reduce surface area |Habit, e.g. nocturnal/burrowing |
|Hairs on leaf to reduce wind velocity |Body covering |
|Shiny surface |Concentration of urine |
|Thick waxy cuticle |Reduced sweat glands |
1 Pie chart to be made up of: 346 degrees for water in oceans and sea as salt water, 14 degrees as fresh water.
2 Water is referred to as a ‘universal solvent’ because it is very versatile and has the ability to dissolve more substances than other solvents.
3 a Examples include photosynthesis in plants, which is essential for the manufacture of sugars, and breathing in animals. Water is a reactant in photosynthesis (CO2 + H2O).
b Water must be available for these processes in order for them to take place....