Biotechnology

Biotechnology

We use biotechnology to alter living things. It gives us the power to create new animals, plants, foods, medicines, materials and even machines. People have used biotechnology for thousands of years to slowly breed new plants, animals and the microorganisms that make cheese, bread, beer, yogurt and wine.

In 1987, geneticist Truda Straede of Australia created spotted cats after breeding toroiseshell cats with Burmese and Abyssinian cats for ten years. Today, modern biotechnology could speed up this breeding process by altering the genetic material deep inside the cells. Scientists have already created bright blue carnations, and tomatoes that ripen on the vine without getting mushy. Biotechnology's potential is enormous. We can even use bacteria grown in laboratories to digest oil to clean up oil spills. The next hundred years will be an age of exciting ”bio-inventions”.

Spot the Difference

In the future, the spot-making genes from a leopard could be mixed in with the genes of a domestic cat to produce a spotted animal.

Killer Cotton

In 1992, an American company altered the genes in some cotton plants so that their leaves became poisonous to caterpillars but nothing else. This reduced the need for harmful insecticides.

Two cats, Jamaica. Photo by Elena.

Strange but True

In 1994, scientists in Australia invented a way of removing fleece from sheep without shearing. They injected sheep with a special hormone then wrapped them in lightweight hairnets. Three weeks later, the fleece could be peeled off the sheep by hand.

Transgenic Pigs

The heart of a pig is similar in shape and size to the human heart. People and pigs, however, have very different genes. Scientists in England have developed a virus that carries human genes into pigs. This makes it possible for the human body to accept the heart of a pig in a transplant.

Changing Genes

Every living cell has spiral-shaped deoxyribonucleic acid (DNA), discovered in 1953 by Francis Crick and James Watson at Cambridge in England. The DNA is made up of genes that control how the cell works. Biotechnhologists have learned how to alter the genes and change living cells.

• 6000 BC: Beer – Mesopotamia.
• 1000 BC: Cheese – Nomad tribes, Middle East.
•  1972: Oil-digesting microbes – Dr. Ananda M. Charkabarty, USA.
• 1975: Monoclonal Antibody – George Kohier and Cesar Milstein, England.
• 1984: Transgenic plant – University of Ghent, Belgium.
• 1986: Black Tulip, Geert Hageman, Netherlands.
• 1989: Gene Shears – James Haseloff and Wayne Gerlach, Australia.
• 1990: Crown Gall Bactericide – Dr. Alan Kerr, Australia.
• 1991: Long-life Tomato, USA.

On a Farm

On a farm

The plow and irrigation have tamed more farmland than any other farming inventions. People first grew crops in the Middle East about 10,000 years ago, but planting, harvesting and watering them by hand was a slow process.

In Egypt and India, nearly 4,500 years later, farmers prepared the ground for planting with wooden plows pulled by oxen. The Egyptians invented a machine called a shaduf, which helped them take water from the River Nile to irrigate or water their crops. Barbed wire was another great farming invention. Farmers used it to divide huge areas of Africa, North America and Australia into separate wheat, cattle and sheep farms in the 1800s. These enormous new farms revolutionized farming. Farmers now needed faster ways of harvesting grain, wool, meat and milk. The old methods were soon replaced by machines that did the work of hundreds of people.

Spade

Wooden spades with iron blades were invented by the Romans about 2,000 years ago.

Barbed wire

In 1867, American Lucien Smith invented barbed wire and made it possible for farmers to fence off their lands.

Cows and barbed wire. Photo by Elena.

Four jobs in one

In 1884, Australian Hugh McKay invented the horse-drawn harvester. It combined cutting, threshing, winnowing and bagging wheat grain into one operation. Combine harvesters with gasoline or diesel engines are now used 24 hours a day, with lights at night, to harvest the crops.

Watering the Crops

The Egyptian shaduf is a little like a seesaw. A long wooden pole, balanced on a crossbeam, has a rope and bucket at one end, and a heavy stone weight to counterbalance it at the other. The weight of the rock makes it easier to lift a heavy bucket of water.

Did you Know?

Superphosphates – aftificial chemicals that enrich the soil – were invented by Sir John Bennett Lawes in England in 1842. But fertilizers often run into the rivers and oceans, killing fish and making algae grow,

Plow

Plows made from wood and stag antlers were invented in Egypt and India about 5,500 years ago. Simple ox-drawn plows are still used on family farms in many countries.

Tractor

Three-wheeled steam tractors, built by the Case company of America in 1829, were very heavy and often became stuck in the soft soil. Modern tractors were pioneered by Henry Ford in 1907.

Time-line

• 1794: Cotton Gin (separator) – Catherine Green and Eli Whitney, USA.
• 1831: Grain Reaper (Cutter) - Cyrus McCormick, USA.
• 1833: Steel Plow – John Lane, USA.
• 1860: Nutriculture – Julius vos Sachs, Germany.
• 1868: Granny Smith Apple – Maria Smith, Australia.
• 1889: Modern Milking Machine, William Murchland, Scottland.
• 1924: Aerial Crop Dusting, USA.
• 1939: Dot Pesticide: Paul Muller, Switzerland.
• 1975: Axial Combine Harvester – International Harvester, New Holland, USA.

The Ways of Water

The Ways of Water

Water covers more than two-thirds of the Earth's surface and is constantly on the move. It rushes along rivers and streams ; it flows into oceans.

This endless movement of water creates energy that can be harnessed. For centuries, people have channeled flowing water into waterwheels that turn to grind grain. Hydroelectric power stations use water in a similar way, but to generate electricity. These enormous concrete constructions are usually found in mountainous regions where there is a high rainfall. Engineers build huge dams across steep-sided valleys. Turbines (modern versions of ancient wooden waterwheels) are placed in the path of the water that gushes with force through the dam. This torrent of water strikes the angled blades of the turbines, which begin to spin and extract an incredible amount of energy from the water. The process of producing hydroelectric power is set in motion.

Control room

The operation of the entire power plant is directed from the control room.

Watering the land

The water for this insectlike irrigation system is coming from the dam of a hydroelectric power station.

Transmission lines

Strengthened electric cables called transmission lines carry electricity away from the power plant.

Way of Water. Photo by Elena.

Spillway

The spillway gates are opened to release water when the level of water behind the dam is too high.

Reservoir

The deep lake that forms behind the dam wall is called a reservoir. The reservoir is built to make sure there is always enough water to operate the generators.

Dam Walls

There are usually curved to withstand the enormous force of water pressing against them. The walls are thicker at the base than the top.

Transformers

Transformers boost the electrical force from the generators to more than 200,000 volts.

Penstock

This channels water from the reservoir through the dam to the turbines

Generators

The spinning turbines are connected by shafts to electricity generators. When the turbines spin, the generators make electricity.

Turbines

Water flowing through tunnels in the dam makes the turbines spin at high speed. Once the energy has been removed, the water flows away through the center of the turbines.

Make Your Own Waterwheel

Cut four pieces of cardboard 1 ½ in x ¾ in and collect an empty thread spool and drinking straw (Step 1) to Glue each piece of cardboard to the thread spool (Step 2) and push the drinking straw through the middle so that your waterwheel can spin easily. Hold the wheel under a running faucet. When water hits the card paddles, the wheel will turn (Step 3).

A Daily Grind

Water-powered hammers are used in Laos in Southeast Asia to grind rice. When the paddles are turned by the flow of the river, the crossbeam at the end of the axle raises the hammer, then releases it to fall on the rice below.

Myths and Legends

Myths and Legends

Using Air and Wind

For thousands of years, people have told stories of wondrous beings that moved through the sky with the grace and ease of the birds. The ability to fly was seen as a sign of greatness and power. The gods and the heroes of many myths and legends were set apart from ordinary people because the could fly. In Greek mythology, Icarus and Daedalus flew on wings made of feathers, twine and wax; King Kaj Kaoos of Persia harnessed eagles to his throne, while Count Twardowski of Poland flew to the moon on the back of a rooster.

Many people were inspired by visions of joining their heroes in the sky. They strapped wings to their arms and jumped off towers, high buildings and even out of balloons. Some did survive their dramatic falls. In 1507, Scotsman John Damian leapt from the walls of a castle with wings made of chicken feathers and broke only his thing. He thought he would have been more successful if he had used the feathers of a bird that could really fly.

The modern hero Superman can fly “faster than a speeding bullet”. It seems our desire to believe in flying heroes continues.

A Sky Bird

The Garuda was a giant bird that carried the Indian god Vishnu across the sky. It is also the name of Indonesia's national airline, which uses the mythical bird for its logo.

A Chariot of Wings

Alexander the Great was said to have flown by harnessing six griffins, mythical winged animals, to a basket. He placed meat on his spear and enticed them to fly after it.

A Winged Horse

According to Greek legend, Bellerophon the Valiant, son of the King of Corinth, captured a winged horse called Pegasus. He flew through the clouds to find and defeat in battle the triple-headed monster, Chimera.

Flying God. Photo by Elena.

Reaching for the Sunday

In Greek mythology, Daedalus and his son Icarus used was-and-feather wings to escape from the island of Crete. But Icarus flew too close to the sun and the was on his wings melted. He fell into the Aegean Sea and drowned.

Tower Jumpers

Through the centuries, humans have tried to copy the birds. With elaborate wings made of feathers, they jumped from towers and flapped their arms desperately as the plummeted to to ground. They did not know that humans are too heavy, and their muscles are not strong enough to fly like birds. The hearts of humans cannot pump blood fast enough to meet the demands of wing flapping, which even in a sparrow is 800 heartbeats a minute.

A Touch of Spring

The Egyptian goddess Queen Isis had wings like a falcon. Each year she flew over the Earth and brought spring to the land.

Sky Battle

In many legends, the forces of both good and evil had the power to fly. St. Michel defended islands against deadly dragons.

King Kong, a legend. Photo by Elena.

Wind Power

Wind Power

Using the elements

People have used the power of the wind for more than 5,000 years. It propelled their sailing boats over rivers, lakes and oceans; it turned the heavy blades of windmills to grind grain and pump water. Wind has energy because it is always moving in one direction or another. This energy can be caught, or harnessed, by large sails or blades.

When electricity was developed in the nineteenth century, wind power did not seem as efficient as this marvelous new source of power, and most windmills disappeared. But wind power is making a comeback. Today, modern versions of windmills called wind turbines are used to generate electricity. Groups of wind turbines with long, thin metal or plastic blades, which look like airplane propellers on top of tall thin towers, are often erected together in wind farms that stretch across the landscape. By the middle of the twenty-first century, one-tenths of the world's electricity could be powered by wind turbines.

Wind-Assisted Tanker

Some ships have stiff fiberglass sails as well as engines. They can save fuel by using sails whenever there is enough wind. Computers calculate the wind speed and indicate when it is time to unfold the sails.

The wind. Photograph by Elena.

Wind Farms

These are buit in very windy areas and are controller by computers that turn their blades into the wind. When the wind turns the blades, the spinning motion is converted into electricity.

Blades: The blades of the turbine are set at an angle that can be changed to suit the wind's speed of direction.

Gearbox: The gearbox, driven by the turbine shaft, controls the speed of the generator.

Generator: The generator converts the spinning motion into electricity.

Turbine shaft: Wind turns the blades, which turn the central turbine shaft. The speed of the shaft varies according to the strength of the wind.

Nacelle: The nacelle (the part that contains the machinery) pivots to keep the blades pointing into the wind. The angle of the blades is set automatically to suit the wind speed.

Tower: The tower holds the blades at a safe height above the ground and contains the cables that cary the electricity underground.

Times past

Windmills were used for many years to grind grain.

Cap: The cap carrying the sails could turn so that the sails faced into the wind.

Canvas-covered sails: Canvas sheeting stretched over the wooden frame of the sails caught the wind and moved the sails around.

Fantail: Wind blowing against the fantail made it spin and turned the mill cap until the sails faced the wind.

Grain hopper: Grain fell from a container, called a hopper, down to the two grindstones below.

Driveshaft: This used the turning motion of the sails to move the grindstones.

Grindstones: Two heavy stones rotated and crushed the grain beneath them.

Make Your Own Windmill

Cut one-third of the way across a square of paper from each corner, and make a small hole in each corner (Step 1). Pull the four corners into the middle of the sheet (Step 2). Fasten pa pushing a tack of drawing pin through the middle. Attach to a drinking straw at the back, making sure your windmill can spin freely (Step 3). Now blow on it or hold it in the breeze.