READING PASSAGE 1

You should spend about 20 minutes on Questions 1-13 which are based on Reading Passage 1 below.

THE PLIGHT OF RICE

Rice is a tall grass with a drooping panicle that contains numerous edible grains and has been cultivated in China for more than 6,000 years. A staple throughout Asia and large parts of Africa, it is now grown in flooded paddy fields from sea level to high mountains and harvested three times a year. According to the Food and Health Organisation of the United Nations, around four billion people currently receive a fifth of their calories from rice.

Recently, Japan, South Korea, and Taiwan have slightly reduced rice consumption due to the adoption of more western diets, but almost all other countries have raised their consumption due to population increase. Yet, since 1984, there have been diminishing rice yields around the world.

From the 1950s to the early 1960s, rice production was also suffering: India was on the brink of famine, and China was already experiencing one. In the late 1950s, Norman Borlaug, an American plant pathologist, began advising Punjab State in northwestern India to grow a new semi-dwarf variety of wheat. This was so successful that, in 1962, a semi-dwarf variety of rice, called IR8, developed by the Philippine ·International Rice Research Institute (IRRI), was planted throughout Southeast Asia and India. This semi-dwarf variety heralded the Green Revolution, which saved the lives of millions of people by almost doubling rice yields: from 1.9 metric tons per hectare in 1950-64, to 3.5 metric tons in 1985-98.

IR8 survived because, as a semi-dwarf, it only grows to a moderate height, and it does not thin out, keel over, and drown like traditional varieties. Furthermore, its short thick stem is able to absorb chemical fertilisers, but, as stem growth is limited, the plant expends energy on producing a large panicle of heavy seeds, ensuring a greater crop.

However, even with a massive increase in rice production, semi-dwarf varieties managed to keep up with population growth for only ten years. In Africa, where rice consumption is rising by 20% annually, and where one-third of the population now depends on the cereal, this is disturbing. At the current rate, within the next 20 years, rice will surpass maize as the major source of calories on that continent. Meantime, even in ideal circumstances, paddies worldwide are not producing what they once did, for reasons largely unknown to science. An average 0.8% fall in yields has been noted in rich rice-growing regions; in less ideal ones, flood, drought and salinity have meant yields have fallen drastically, sometimes up to 40%.

The sequencing of the rice genome took place in 2005, after which the IRRI developed genetically modified flood-resistant varieties of rice, called Sub 1, which produce up to four times more edible grain than non-modified strains. In 2010, a handful of farmers worldwide were planting IRRI Sub 1 rice; now, over five million are doing so. Currently, drought- and salt-resistant varieties are being trialled since most rice is grown in the great river basins of the Brahmaputra, the Irrawaddy, and the Mekong that are all drying up or becoming far saltier.

With global warming, many rice-growing regions are hotter than 20 years ago. Nearly all varieties of rice; including IR8, flower in the afternoon, but the anthers – little sacs that contain male pollen – wither and die in soaring temperatures. IRRI scientists have identified one variety of rice, known as Odisha, that flowers in the early morning and they are in the process of genetically modifying IR8 so it contains Odisha-flowering genes, although it may be some time before this is released.

While there is a clear need for more rice, many states and countries seem less keen to influence agricultural policy directly than they were in the past. Some believe rice demand will dip in wealthier places, as occurred in Japan, South Korea, and Taiwan; others consider it more prudent to devote resources to tackling obesity or to limiting intensive farming that is environmentally destructive.

Some experts say where there is state intervention it should take the form of reducing subsidies to rice farmers to stimulate production; others propose that small landholdings should be consolidated into more economically viable ones. There is no denying that land reform is pressing, but many governments shy away from it, faring losses at the ballot box, all the while knowing that rural populations are heading for the city in droves anyway. And, as they do so, cities expand, eating up fertile land for food production.

One can only hope that the IRRI and other research institutions will spearhead half a dozen mini green revolutions, independently of uncommitted states.

Questions 1-5

Do the following statements agree with the information given in Reading Passage 1?

In boxes 1-5 on your answer sheet, write:

TRUE               if the statement agrees with the information.

FALSE              if the statement contradicts the information.

NOT GIVEN    if there is no information on this.

1   Rice is only grown at a low elevation.

2   Rice has been cultivated in Africa for 3,000 years.

3   Since 1984, rice yields have decreased due to infestations of pests.

4   Norman Borlaug believed Punjabi farmers should grow semi-dwarf rice.

5   The Green Revolution increased rice yields by around 100%.

Questions 6-11

Complete the notes below.

Choose ONE WORD AND / OR A NUMBER from the passage for each answer.

Write your answers in boxes 6-11 on your answer sheet.

Questions 12-13

Choose the correct letter A, B, C, or D.

Write the correct letter in boxes 12-13 on your answer sheet.

12   States are more interested in………than stimulating rice production.

A   increasing wheat production

B   reducing farm subsidies

C   confronting obesity

D   consolidating land holdings

13 ……..disappearing as urbanisation speeds up.

A   Intensive farming is

B   Fertile land is

C   Clean water is

D   Agricultural institutes are

READING PASSAGE 2

You should spend about 20 minutes on Questions 14-26 which are based on Reading Passage 2 below. 

A New Perspective on Bacteria

A

Microbes are organisms too small to be seen by the naked eye, including bacteria, blue-green algae, yeasts, fungi, viruses, and viroids.

A large, diverse group, almost all bacteria are between one and ten µ¹ (larger ones reach 0.5 mm). Generally single-celled, with a distinctive cellular structure lacking a true nucleus, most bacterial genetic information is carried on a DNA loop in the cytoplasm² with the membrane possessing some nuclear properties.

There are three main kinds of bacteria – spherical, rod-like, and spiral – known by their Latin names of coccus, bacillus, and spirillum. Bacteria occur alone, in pairs, clusters, chains, or more complex configurations. Some live where oxygen is present; others, where it is absent.

The relationship between bacteria and their hosts is symbiotic, benefitting both organisms, or the hosts may be destroyed by parasitic or disease-causing bacteria.

B

In general, humans view bacteria suspiciously, yet it is now thought they partly owe their existence to microbes living long, Jong ago.

During photosynthesis, plants produce oxygen that humans need to fuel blood cells. Most geologists believe the early atmosphere on Earth contained very little oxygen until around 2½ billion years ago when microbes bloomed. Ancestral forms of cyanobacteria, for example, evolved into chloroplasts – the cells that carry out photosynthesis. Once plants inhabited the oceans, oxygen levels rose dramatically, so complex life forms could eventually be sustained.

The air humans breathe today is oxygen-rich, and the majority of airborne microbes are harmless, but the air does contain industrial pollutants, allergens, and infectious microbes or pathogens that cause illness

C

The fact is that scientists barely understand microbes. Bacteria have been proven to exist only in the past 350 years; viruses were discovered just over 100 years ago, but in the past three decades, the ubiquity of microbes has been established with bacteria found kilometres below the Earth’s crust and in the upper atmosphere. Surprisingly, they survive in dry deserts and the frozen reaches of Antarctica; they dwell in rain and snow clouds, as well as inside every living creature.

Air samples taken in 2006 from two cities in Texas contained at least 1,800 distinct species of bacteria, making the air as rich as the soil. These species originated both in Texas and as far away as western China. It now seems that the number of microbe species far exceeds the number of stars.

D

Inside every human being, there are trillions of bacteria with their weight estimated at 1.36 kg in an average adult, or about as heavy as the brain. Although tiny, 90% of cells in a human are bacterial. With around eight million genes, these bacteria outnumber genes in human cells by 300 times.

The large intestine contains the most bacteria – almost 34,000 species – but the crook of the elbow harbours over 2,000 species. Many bacteria are helpful: digesting food; aiding the immune system; creating moisturiser; and, manufacturing vitamins. Some have highly specialised functions, like Bacteroides thetaiotaomicron, which breaks down plant starch, so an infant can make the transition from mother’s milk to a more varied diet.

Undeniably, some bacteria are life-threatening. One, known as golden staph, Staphylococcus aureus, plagues hospitals, where it infects instruments and devours human tissue until patients die from toxic shock. Worse, it is still resistant to antibiotics.

E

Antibiotics themselves are bacteria. In 1928, Alexander Fleming discovered that a mould in his laboratory produced a chemical he named penicillin. In 1951, William Bouw collected soil from the jungles of Borneo that eventually became vancomycin. Pharmaceutical companies still hunt for beneficial bacteria, but Michael Fischbach from the University of California believes that the human body itself is a ready supply.

F

Scientific ignorance about bacteria is largely due to an inability to cultivate many of them in a laboratory, but recent DNA sequencing has meant populations can be analysed by a computer program without having to grow them.

Fischbach and his team have created and trained a computer program to identify gene clusters in microbial DNA sequences that might produce useful molecules. Having collected microbial DNA from 242 healthy human volunteers, the scientists sequenced the genomes of 2,340 different species of microbes, most of which were completely new discoveries.

In searching the gene clusters, Fischbach et al fund 3,118 common ones that could be used in pharmaceuticals, for example, a gene cluster from the bacterium Lactobacillus gasseri, successfully reared in the lab, produced a molecule they named lactocillin. Later, they discovered the structure of this was very similar to an antibiotic, LFF571, undergoing clinical trials by a major pharmaceutical company. To date, lactocillin has killed harmful bacteria, so it may also be a reliable antibiotic.

G

Naturally, the path to patenting medicine is strewn with failures, but, since bacteria have been living inside humans for millions of years, they are probably safe to reintroduce in new combinations and in large amounts.

Undoubtedly, the fight against pathogens, like golden staph, must continue, but as scientists learn more about microbes, respect and excitement for them grow, and their positive applications become ever more probable.

¹A micron= 10^-6 m

²Material inside a cell

Questions 14-18

Passage 2 has seven sections, A-G.

Which section contains the following information?

Write the correct letter A-G, in boxes 14-18 on your answer sheet.

NB:  Any section can be chosen more than once.

14   examples of bacteria as a patented medicine

15   a description of bacteria

16   gene cluster detection and culture

17   humans are teeming with bacteria

18   Fischbach’s hypothesis

Questions 19-22

Choose the correct letter A, B, C, or D.

Write the correct letter in boxes 19-22 on your answer sheet.

19   What do almost all bacteria share?

A   Their simple configurations

B   Their cellular organisation

C   Their survival without oxygen

D   Their parasitic nature

20   From the suffix ‘-bacillus’, what shape would you expect the bacterium Paenibacillus to be?

A   spherical

B   rod-like

C   spiral

D   amorphous

21   Why were ancient bacteria invaluable to humans?

A   They contributed to higher levels of oxygen.

B   They reduced widespread industrial pollution.

C   They protected humans from intestinal ailments.

D   They provided scientists with antibiotics.

22   How prevalent are microbes?

A   Not at all

B   Somewhat

C   Very

D   Extremely

Questions 23-26

Answer the questions below.

Choose NO MORE THAN THREE WORDS OR A NUMBER from the passage for each answer

Write your answers in boxes 23-26 on your answer sheet.

23   Which organ does the total weight of bacteria in a human body equal?

24   Roughly how many bacterial species live in a human’s large intestine?

25   In Fischbach’s view, where might useful bacteria come from in the future?

26   What do some scientists now feel towards microbes?