Test 09 on genral biology and genetics

I. Прочитайте текст и выберите вариант ответа, соответствующий содержанию прочитанных фрагментов (А-D).

A. In the 5,000 years or so of recorded history, the human race has changed remarkably little physically. The men and women of ancient Egypt were very little different from today, in fact. This is because our biological makeup is determined by genes and no matter what we do in our lifetime, we cannot alter our genes.

B. The way we live does affect certain things though. Take life expectancy, for example. For most of human history, men could expect to live around 40 years and women a few years less. The number fluctuated a bit, in actual fact. It was 45 years in Classical Greece – that's around 650 BC – but it fell to 40.2 in the time of the Roman Empire in the second century AD, and fell again to 37.7 years by the Middle Ages in around 1400. That's for men. For women, it was a similar pattern. They could expect to live 31.1 years in the Middle Ages, compared with Roman times when they had a life expectancy of 34.6 years. In the past 100 years, though, there have been such huge advances in medicine that many of the infectious illnesses people used to die of can be easily treated. So now, in the West, men can expect to live to 70 and women even longer – till they are 76.

C. Then there's the question of infant mortality. In the past, it was extremely common for children to die soon after they were born. So people tended to have quite a few children. For families in Classical Greece, for example, the number of births was 4.3 on average, as you can see on the chart, but only 2.7 of those children survived to adulthood. In Roman times, the number of births was down a little to 3.7 with approximately 2 children surviving. Then, in the Middle Ages, the survival rate dropped drastically. Families had 4 or more children on average and only 1.6 of them survived. Nowadays, with greatly improved post natal care, the situation is much, much better. Families have around 2.2 children and the majority grow up fit and well.

D. As average life expectancy continues to rise, the question is whether there is any limit on the human lifespan. Could people in the 21st century survive to be 125? Unfortunately, the answer seems to be 'no'. The current view is that, with a few exceptions, the natural human lifespan is around 85 years.

1. The average age for both men and women used to be

A. 50 years

B. 40 years

C. 30 years

D. 60 years

2. If a woman can expect to live till about 76 she probably lives in

A. Africa

B. Classical Greece

C. the West

D. the East

3. Less than one third of all children survived in

A. Classical Greece

B. Roman Empire

C. Medieval Europe

D. Ancient Egypt

4. We can refer an average family with two or three healthy kids to

A. Elizabethan England

B. Jacobean France

C. Classical Greece

D. contemporary USA

5. People lived the least in

A. Classical Greece

B. Roman Empire

C. Medieval Europe

D. Western world

II. Прочитайте текст. Подберите соответствующий заголовок к каждому абзацу (1-5).

(1) Forty million years ago, when the earth was much wetter and warmer, huge forests with many kinds of trees thrived in the far north. Out of some of these trees, stretching as tall as ten-story buildings oozed a sticky resin. Mosquitoes buzzed through the forests, and grasshoppers and crickets leaped, and ants and spiders scurried by the trees in search of food. If they carelessly let a leg or wing touch the resin they were stuck, preserved like mummies in an airtight trap. Millions of years passed, and the climate of the earth altered dramatically. The northlands turned cold and icy. The giant trees fell, buried under the salt water that now covered the land. Far beneath the water, the globs of resin slowly changed, hardening into solid, glowing pieces of amber.

(2) Still millions of years later, storms at sea broke the amber free and tossed it onto beaches for early cave dwellers to find. The cave dwellers wondered if the strange golden stone, warm to the touch, could be solid sunlight. They carved pieces of amber into the shapes of animals or the sun and wore them on cords around their necks for magical protection. When early Chinese people found amber the color of tigers' stripes, they believed it held the souls of dead tigers and they treasured it as a source of courage. The ancient Greeks rubbed amber against cloth or animal skins to polish it and make it glow, they noticed that the amber would pull feathers or pieces of straw to it. They had discovered static electricity. For hundreds of years, people used amber to decorate warriors' weapons; some soldiers braided amber beads in their horses' manes to ensure success in battle. Amber was also ground fine and mixed with honey, oil of roses, and crabs' eyes or claws for use as medicine. Amber mixtures were believed to cure earaches, headaches, and any number of diseases.

(3) In the early 1700s, King Frederick I of Prussia had an entire room built from 100, 000 pieces of amber of many colors — yellow, orange, red, brown, and even blue and green — all fitted together like a giant jigsaw puzzle. The room was used and admired for more than 200 years, but in the 1940s, during World War II, it was taken apart and loaded into boxes for storage in a safer place. The boxes were somehow lost, and where the amber room is today remains a mystery.

(4) The pieces of amber with inclusions of early life or gas bubbles are the most valuable to scientists. They hold clues about the earth's ecology millions of years ago and enable scientists to compare early life forms with today's. More than a thousand kinds of insects have been found preserved in amber, from prehistoric flies that proved to be the ancestors of our houseflies to a 140-million-year-old weevil that lived at the time of the dinosaurs. Although most of the preserved insects are now extinct, their descendants may still survive, sometimes in new places. A termite found in Mexican amber now lives only in Australia.

(5) Scientists use X-rays to study skeletons of frogs and lizards, seeds inside fruit, and other inclusions without opening the amber. They also scan the surface of ancient mummified insects with electron microscopes, revealing such detail as preserved muscle fibers and the spinning glands of trapped spiders. In addition, scientists can extract DNA directly from an amber inclusion. Amber is the only known fossil from which ancient DNA can be recovered.

A. Mysterious Loss of Amber Room

B. Use of Amber throughout Millennia

C. Discovery of Static Electricity

D. Amber and Its Role in Science

E. Giant Jigsaw Puzzle

F. How Amber Appeared

G. Scientific Research Methods

III. Прочитайте текст и выполните послетекстовые задания.

(1) The shark's teeth aren't found just in its mouth but over its whole body. The real name of these growths is "dermal denticles," meaning skin teeth, but they're actually the shark's scales. Normally these miniature teeth can only be seen with a magnifying glass but they cover the skin like a thick forest. They are similar to human teeth, made of blood vessels, pulp, and enamel, but they're differently shaped.

(2) The denticles begin to grow while the shark is still an embryo inside its mother. Appearing as tiny forms called papilliform growths, they stay just under the skin and harden as lime salts from the mother's body are deposited on them. The deposits' build up until the dermal denticles are fully formed. The denticles then emerge through the skin. Their bases are calcified, like human teeth, and their roots reach beneath the hide into the dermis, or deeper skin, of the shark. Each denticle is held in place by the same tough connective fibers that hold the shark's teeth inside its mouth.

(3) When fully grown, these denticles resemble tiny spines reaching out of the skin, curving backward toward the tail fin. The first row of these minute teeth appear just outside the large teeth of the mouth and form a dense, crisscrossing pattern over the entire body. They may grow so close together that the skin beneath cannot be seen, even under a magnifying glass, or they may be so sparse that the skin can clearly be seen. Because of the denticles, shark skin was used by knights who wanted a material to keep their swords from slipping out of their hands during battle.

(4) This toothed skin probably began to appear when skeletons were evolving in most other animals. Sharks have no bones. It means that they have only their skin to hold their vital organs in place. Shark skin must be extraordinary to serve this purpose, and it is. Under the buoyant pressure of ocean water, the skin keeps the shark compact and sleek. Although dermal denticles are tough, they suffer a great deal of damage from the shark's daily activities. Healthy denticles can only be found toward the rear of a shark, along its sides. Other areas, such as the leading edge of the first dorsal fin or the tip of the snout, are most likely to rub against something, and those denticles become worn and unidentifiable.

Выберите вариант ответа, соответствующий содержанию прочитанного текста (задания 1-5).

1. The name of the growths mentioned in the text can be translated as

A. shark's scales.

B. skin-formed teeth.

C. teeth growing on skin.

2. The denticles begin to grow when the shark is

A. still a fetus.

B. little and totally dependent on its mother.

C. several months old and has accumulated enough calcium in its organism.

3. The dentacles may grow close together

A. yet the skin beneath can be easily seen under a magnifying glass.

B. so that even a magnifying glass won’t help to discern the skin.

C. but the skin is visible.

4. Shark skin was used by knights who wanted some material

A. to make strong armor.

B. to prevent their swords from corrosion.

C. for the sword handles.

5. Shark's dermal denticles are an effective means to

A. protect the shark's skin from injury.

B. make the shark's body compact and sleek under the pressure of ocean water.

C. preserve the shark's vital organs.

Определите значение указанного слова в тексте (задания 6-8).

6. minute (3)

A. slight B. tiny C. mind

7. sleek (4)

A. smooth B. glossy C. straight

8. emerge (2)

A. become B. appear C. develop

III. Выберите правильный вариант перевода в соответствии с содержанием текста (задания 9-12).

9. When fully grown, these denticles resemble tiny spines, reaching out of the skin… (3)

A. Полностью сформированные зубчики напоминают крошечные позвонки, выступающие из кожи..

B. Полностью сформированные зубчики сродни небольшим позвонкам, достигающим кожного покрова.

C. Когда эти зубчики полностью сформировались, они напоминают крошечные позвонки, выступающие из кожи.

10. This toothed skin probably began to appear when skeletons were evolving in most other animals (4).

A. Эта зубчатая кожа, скорее всего, начала появляться тогда, когда позвоночник эволюционировал у большинства животных.

B. Эта "зубастая" кожа появилась тогда, когда большинство животных стали позвоночными.

C. Эта зубчатая кожа, скорее всего, появилась тогда, когда у большинства других животных уже были развитые позвоночники.

11. Shark skin must be extraordinary to serve this purpose… (4)

A. Кожа акулы должна быть необычной, чтобы служить этой цели

B. Кожа акулы, должно быть, необычная, если она служит этой цели.

C. Кожа акулы должна быть необычной, чтобы обслуживать эту цель.

12. Although dermal denticles are tough, they suffer a great deal of damage from the shark's daily activities (4).

A. Хотя кожные зубчики и крепки, они получают значительные повреждения в процессе ежедневной жизнедеятельности акулы.

B. Поскольку кожные зубчики довольно крепки, они подвергаются серьёзным испытаниям во время ежедневной активности акулы.

C. Кожные зубчики подвержены серьёзным повреждениям во время ежедневной активности акулы, но они достаточно крепкие.