End of Unit 2 Test

1

Heroism involves acting courageously, usually for a good purpose. The term also suggests that the act requires great effort. It was used to describe daring actions for the benefit of others in ancient Greek and Roman myths. For example, Prometheus wanted humans to have fire, which Zeus had taken away from them. Prometheus risked Zeus’ anger and punishment to give fire to humans again.

2

The word heroism is often used now to describe the work of first responders at an accident or a natural disaster. We often celebrate firefighters and police officers, as well as other people who help in a crisis, for their displays of heroism. Like mythic heroes, these first responders show the essential traits of heroism: performing courageous and difficult actions that benefit others.

1

Balto was a sled dog whose heroic actions helped save children’s lives. In January 1925, the city of Nome, Alaska, experienced a terrible outbreak of diphtheria. Children weren’t strong enough to recover from the disease without medicine, but the nearest serum was in Anchorage, Alaska, 1,000 miles away.

2

The serum was transported from Anchorage to the town of Nenana by train. Getting the serum from Nenana to Nome, however, was a problem. There was no train to Nome. The Arctic weather, including blizzards and extreme cold, ruled out transportation by airplane. To help, more than 20 brave sledders and 150 dogs carried the medicine from Nenana to Nome in relays for 674 miles. They accomplished this feat even though strong winds sometimes lifted the dogs and sleds, and the average temperature was 40 to 50 degrees below zero.

3

It took nineteen dogsled teams averaging six miles an hour for five days and seven hours to deliver the serum. Under typical conditions, dogsleds on that route usually took about twenty- five days to cover that distance. When the medicine arrived in Nome, Balto was the lead dog, with six others on the team.

4

As the dog sled teams raced against time, people around the world breathlessly followed their progress in newspapers and on the radio. The coverage helped make Balto a global sensation. In 1925, his fans in New York City—thousands of miles away from Nome—honored Balto by installing a statue of him in Central Park. The statue stands there to this day.

5

Gunnar Kaasen, the driver of the last team on the run to Nome, agreed with the public that Balto was an exceptional dog. He told reporters after the trip, “I couldn’t see the trail. Many times, I couldn’t even see my dogs, so blinding was the gale. I gave Balto, my lead dog, his head and trusted him. He never once faltered. It was Balto who led the way. The credit is his.”

This excerpt is a story traditionally told by the Cherokee. It has been adapted from the version collected and published by James Mooney.

1

In the beginning, the Deer had no horns and his head was smooth. He was a great runner and the Rabbit was a great jumper, and the animals were all curious to know which could go farther in the same amount of time. They talked about it a good deal, and at last arranged a match between the two and made a nice, large pair of antlers as a prize for the winner. The Deer and the Rabbit were to start together from one side of a thicket and go through it, then turn and come back, and the one who came out first was to get the horns.

2

On the day fixed all the animals were there, with the antlers put down on the ground at the edge of the thicket to mark the starting point. While everybody was admiring the horns, the Rabbit said: “I want to take a look through the bushes where I am to run.” They thought that all right, so the Rabbit went into the thicket. He was gone so long that at last the animals suspected he must be up to one of his tricks. They sent a messenger to look for him, and away in the middle of the thicket he found the Rabbit gnawing down the bushes and pulling them away until he had a road cleared nearly to the other side.

3

The messenger turned around quietly and came back and told the other animals. When the Rabbit came out at last, they accused him of cheating. He denied it until they went into the thicket and found the cleared road. They agreed that such a trickster had no right to enter the race at all, so they gave the horns to the Deer, who was declared to be the best runner, and he has worn them ever since. They told the Rabbit that, as he was so fond of cutting down bushes, he might do that for a living, and so he does to this day.

Introduction

1

A gene (JEEN) is a kind of messenger in the body of a living creature. Genes are located in the cells of an organism on thread-like structures called chromosomes. Each gene contains and transmits specific information about what an organism will look like and how it will behave.

Barbara McClintock’s Story

2

The next time you enjoy an ear of corn, think of a scientist named Barbara McClintock. Born in 1902 in Hartford, Connecticut, she began studying plants at the Cornell College of Agriculture at age seventeen. She continued her studies after graduating in 1923. Cornell College would not hire women to teach, but McClintock did research there for two years. In 1941, she moved to New York to work at the Cold Spring Harbor Laboratory. She remained there the rest of her working life.

3

McClintock developed new ways to study cells under a microscope. She was interested in patterns of color in kernels of maize, or corn—especially how the purple kernels developed. She knew that genes controlled such traits as the kernels’ color.

4

Genes carry the code that defines an organism’s basic characteristics. Before McClintock, scientists thought that every gene had its own place in a chromosome. However, McClintock discovered a type of gene that can move within and between chromosomes, called “jumping” genes.

5

McClintock suggested that these “jumping” genes control the genes that set the color of the maize kernels and control other genes as well. It was discovered later that some “jumping” genes are nature’s original computer hackers, copying an organism’s individual information and sharing it with others. The gene copies a piece of genetic code from one bacterium, jumps to another, and then downloads the code. In this way, “jumping” genes may help spread resistance to antibiotics among bacteria.

6

For years, the scientific community mostly ignored McClintock’s findings. One reason may have been that people of the time did not fully understand the structure of genes. Once science advanced further, the significance of her discoveries became clearer. By the 1970s, studies had proved Barbara McClintock’s discoveries about genes to be true. Scientists discovered new examples of “jumping” genes. New theories of genes helped them understand how “jumping” genes worked. Now, it was easier to see the importance of McClintock’s early discoveries. In 1983, she won the world-famous Nobel Prize for the category of Physiology or Medicine.