Water For Life

The earth is made up of about 65% water yet only a small % of this is drinkable. This percentage is closest to

• 20
• 60
• 3
• 11

Water molecules have a negatively charged end and a positively charged end . This property means that water is

• polar and has surface tension
• non polar and has surface tension
• liquid at room temperature
• dissolves  non polar substances

These potato slices had a mass of 100 g. They were put in an oven and dehydrated for 3 days. Their dried mass was 20g. What % of potato is water

• 20%
• 80%
• 100%
• 60%

A plant living in the dessert would posses which adaptations to survive

• large leaves and long tap roots
• sunken stomates and fast growth
• sunken stomates and small silver leaves
• water storage trunk and lange leaves

The desert Bilby excretes uric acid crystals instead of liquid urine. This is

• a structural adaptation to conserve water
• a physical feature to stop overheating
• a behavioural adaptation to avoid heat loss
• a physiological adaptation to conserve water

The desert mouse has large ears . These ears are

• a structural adaptation to aid in heat loss
• a behavioural adaptation to aviod heat loss
• a behavioural adaptation to conserve energy
• a structural adaptation to absorb heat

The spinifex rolls its leaves to conserve water This works because

• By rolling its leaves it reflects more heat
• rolling protects the stomates on the underside of the leaf from direct sn
• rolling increases the rate of transpiration
• rolling protects the grass from the wind

Gum trees have a number of adaptations to survive dry weather. These include

• dropping leaves and turning their pale side to the sun
• wind borne seeds
• water storage in their trunk
• large leaves with a thin cuticle

Australia suffers from saline soils in some areas. Here salt has risen to the top of the soil ,poisoning it. The main cause of salinity is

• Ploughing soils
• removing large trees
• growing crops
• irrigation

A fertiliser 

• is a chemical that kills insects
• can be organic or inorganic
• makes plants flower
• contains every nutrient a plant needs