What is bonsai?

Bonsai means “tree in a pot” in Chinese and is pronounced BONE-sigh. It is a special method for growing trees or shrubs in a pot, tray, or dish, which results in an artificially dwarfed plant.

Bonsais are regular trees or shrubs, such as juniper or cypress, that are stunted by pruning their roots and tying their branches with wire. The art originated in China around 200 C.E., and was adapted by the Japanese early in the sixth and seventh centuries.

Why does my dog sometimes howl?

Like barking, growling, and whining, howling is one of the few forms of verbal communication that dogs have. Its roots go back to dogs’ wolf ancestry, when wild wolves used howling to communicate over long distances. The howl swept through different pitches, which helped the sound carry over longer distances. Wolves use howling to let other pack members know their precise location if they happen to get separated.

Other members of the pack howl back in reply—an acknowledgement that the sent message has been received. Wolves also howl to discourage a rival pack from encroaching on their territory. Dogs today still display some of this behavior. If you leave your house or apartment, your dog may howl to try to reestablish contact with you. If the howling persists after you’ve left, it could be a sign of separation anxiety. And sometimes dogs howl to establish their territory.

Why does a swimming pool appear less deep than is actually is?

The rays of light coming from the bottom of the pool pass from a denser medium (water) to a rarer medium (air) and are refracted (bend away from the normal).

When the rays return to the surface, they form an image of the bottom of the pool at a point, which is little above the real position.

What does the immune system do?

The immune system protects the human body against germs, which are microorganisms that cause sickness and disease. There are four major types of germs— harmful bacteria (pathogens), viruses, fungi, and protozoa. This defense system begins with the skin, which stops germs from getting into your blood or tissues. If germs get into your body, for example through your nose or mouth, white blood cells called phagocytes and lymphocytes attack them. Phagocytes scout out and destroy invaders, and long-living lymphocytes remember the invaders and release chemicals called antibodies to make the body resistant, or immune, to them.

White blood cells live in the bloodstream, lymphatic system, and spleen. The lymphatic system (or lymph system, for short) is a far-reaching network that extends throughout your entire body. A clear liquid called lymph runs throughout the system, washing the body’s cells with nutrients and water and detecting and removing pathogens. Lymph is filtered through the lymph nodes, and then passes into the body’s bloodstream.

How is cotton harvested?

Cotton, which comes from flowering Gossypium plants, is a key vegetable fiber used for making clothes, and oil from its seeds can be used in cooking or for making soap. The cotton plant grows in 17 states that make up the U.S. “Cotton Belt”: California, Arizona, New Mexico, Texas, Oklahoma, Arkansas, Missouri, Mississippi, Alabama, Louisiana, Florida, Tennessee, North Carolina, South Carolina, Virginia, Georgia, and Kansas. In the United States, where cotton is no longer picked by hand, machines called pickers or strippers harvest the crops.

Cotton-picking machines have spindles that pick (twist) the seed cotton from the burrs that are attached to plants’ stems. Doffers— a series of circular rubber pads—then remove the seed cotton from the spindles and knock the seed cotton into a conveying system. Conventional cotton stripping machines use rollers equipped with alternating bats and brushes to knock the fluffy white bolls, which contain seeds and hairs, from the plants into a conveyor. After harvest, most of the cotton is pressed into large blocks for storage. These cotton bundles are then transported to the cotton gin, a machine that pulls out the seeds from the cotton bolls.

Would it hurt if a plant-eating dinosaur bit you?

Absolutely. Being bitten by a plant-eating dinosaur such as Brachiosaurus, with its 52 chisel-like teeth, would certainly hurt! The bite of a Parasaurolophus, with its interlocking rows of teeth, might take off your fingers. In the Iguanodon, numerous sharp teeth were set in rows in the upper and lower jaws, and at steep angles to each other.

When the teeth were pressed together, the upper jaw was forced outward, creating a grinding motion between the teeth and its meal of crushed plant tissue.

Why are there “bulls” and “bears” in the stock market?

An eighteenth-century proverb mocks the man who “sells the bearskin before catching the bear.” A “bearskin speculator,” like the man in the proverb, sold what he didn’t yet own, hoping that the price would drop by the time he had to pay for it. “Bulls” speculate, hoping the price will rise.

The analogies come from a time when fights were staged between the two animals, in which a bear needed to pull the bull down while the bull fought by lifting the bear with its horns.

Why do butterflies and other insects fly from flower to flower?

Butterflies and other insects fly from one plant to the next to feed on the sweet nectar— and sometimes the pollen—located in the interior of flowers. The sugar in nectar supplies insects with the energy they need, and pollen contains protein, fat, vitamins, and minerals. In the process of feeding, many insects transfer pollen—which sticks to their bodies—from one plant’s flower to another.

Pollen, which is a fine powdery grain from a flower’s male reproductive organ, must be transferred to the female reproductive organ of a flower for fertilization to take place and seeds to form.

Why is blood red?

As the young red blood cell grows and takes on an adult form in the marrow of the bone, it loses its nucleus, and it increases its production of hemoglobin. Hemoglobin is the red pigment, or color of blood, and contains iron, combined with protein. (Oxygen combined with iron is red; the more oxygen iron has bound to it, the redder it is.)

When blood passes through the lungs, oxygen attaches itself to the hemoglobin of the red cells. From there, the red cells carry the oxygen through the arteries and the capillaries to all other cells of the body. The arteries appear reddish because the iron in the blood gives up its oxygen to the cells that need it as the red blood cells travel throughout the body. By the time the blood is back on its way to the heart and then to the lungs it has less than half as much oxygen as it did before. The veins, therefore, do not get as much oxygen as the other tissues and they appear bluish.

Why do husbands and wives divorce?

Husbands and wives divorce when they can no longer live happily together. It is usually a sad thing, because when people marry they expect to be with their partner for the rest of their lives. But over the course of a marriage things happen, people can change, and the happiness that the couple was so sure of in the beginning sometimes disappears. When couples with children get divorced it is even more unfortunate because more people are affected. Many children feel bad when their parents divorce because their family will not be the same. After a divorce, they generally do not see one of their parents as much as they did before.

Still, just because the feelings between a mother and a father change doesn’t mean that their love for their children changes in any way. It’s important to remember that divorce is something that happens between a husband and wife—it has nothing to do with the kids. Many children feel that if they adjust their behavior somehow their parents will want to stay together, but divorces are not caused by anything children do.