THERE HAS BEEN A CONSIDERABLE FALL IN THE VALUE OF STERLING IN TH...

70. There has been a considerable fall in the value of sterling in the past week.

VI. ERROR IDENTIFICATION (10 marks)

Water scarcity is fast becoming one of the major limited factors

limiting

in world crop production. In many areas, poor agricultural

………

practices have led to increasing desertification and the loss of

………

formerly arable lands. Consequently, those plants species that are

well adapted with survival in dry climates are being looked at for

to

an answer in development more efficient crops to grow on

developing

marginally arable lands.

Plants use several mechanisms to ensure their survival in desert

environments. Some involve pure mechanical and physical

purely

adaptations, such as the shape of the plant’s surface, smaller

leafed size, and extensive root systems. Some of the adaptations

leaf

are related to chemical mechanisms. Many plants, such as cacti,

have internal gums and mucilages which give them water-

Another

retaining properties. Other chemical mechanism is that of the

epicuticular wax layer. This wax layer acts as an impervious

of

cover to protect the plant. It prevents excessive loss from internal

moisture. It also protects the plant from external aggression,

which can come from inorganic agents such as gases, or organic

agents which include bacteria ant plant pets.

Researchers have proposed that synthetic waxes with similar

protective abilities could be prepared based on knowledge of

is

desert plants. If is successfully developed, such a compound

increase

could be used to greatly increasing a plant’s ability to maintain

health in so adverse situations as inadequate water supply,

such

limited fertilizers availability, attacked by pets, and poor storage

after harvesting.