Category: Lifestyle

A cow, like all mammals, produces milk to feed its young. If its calf nurses regularly, the mother cow’s mammary glands will produce enough milk to give the baby animal all the food it needs. Gradually a calf will nurse less as grass and other feed makes up more of its diet. A mother cow, in turn, will produce less milk until it is no longer needed. But by milking the cows regularly—two or three times a day—dairy farmers can cause the cows to continue producing milk. Certain breeds of cows are particularly good at milk-making, producing 18–27 pints (around 2–3 gallons, or 10–15 liters) each day.

A cow’s large, round udder, located on its underside, has four nipples, or teats, that are squeezed to release stored milk. While once done by hand, milking is done on modern dairy farms by machines with suction hoses, which do the job more quickly and cheaply. Tank trucks collect milk from farms daily and take it to processing plants where it is pasteurized (made germ-free) and used to make dairy products like cheese, butter, and ice cream.

Known as the “Giant Water Platter,” South America’s giant Amazon water lily has strong leaves that reach 6 to 8 feet (1.8 to 2.4 meters) across and can support the weight of a child. The water lilies produce flowers that open at night and are the size of a dinner plate. The first night they are white female flowers; on the second night they turn to pink male flowers.

Beetles and sphinx moths that live in the Amazon River region pollinate the flowers and the seedpods—that are the size of a baby’s head—sink beneath the water, where they lay dormant in the mud for up to four years before germinating. The plant lays dormant for a period every year before producing more leaves that increase in size before it flowers again. However, the giant water lily’s leaves are not the biggest on Earth. Palm trees can grow leaves up to 65 feet (20 meters) long!

The dandelion and the daisy are both named for a particular physical characteristic. The English daisy, with its small yellow centre and white- or rose-coloured rays, closes at night and reopens with daylight like the human eye, and so it was named the “day’s eye.”

The dandelion, because of its sharp, edible leaves, was named by the French “dent de lion,” the “tooth of a lion.”

The first primitive plants appeared on land about 470 million years ago. But these plants did not look like the lush greenery we see in the world today. Rather, they were rootless patches of thin, leaflike plants called liverwarts, so named because some species look like green livers. Liverwarts used a specialized filament (called a rhizoid) to absorb water and stick to rocks.

Fossils reveal that the first true plants to colonize land appeared about 420 million years ago. These plants included flowerless mosses, horsetails, and ferns. They reproduced by throwing out spores, or minute organisms that carried the genetic blueprint for the plant. The ferns eventually bore seeds, but not until about 345 million years ago. Plants with roots, stems, and leaves (called vascular plants) evolved about 408 million years ago.

Earrings were used by seamen, especially warriors such as pirates, for very practical reasons and not for decoration. They were given to young sailors as a symbol of their first crossing of the equator, and their purpose was to protect the eardrums during battle.

The pirates, especially those who fired the ships’ cannons during closed combat with the enemy, dangled wads of wax from their earrings to use as earplugs.

Some buildings are called skyscrapers because they are of great height and have an iron or steel frame inside that supports its floors and walls. Before builders figured out how to make such frames, stone or brick walls had to bear the weight of structures, which could not stand up if they were made too high. And tall stone or brick buildings had to have very thick walls on lower floors to bear the weight of the walls and floors above them. These thick walls wasted a lot of useful space. Because cities have limited land, builders experimented with materials and construction methods in an effort to construct taller buildings that were more practical.

Finally, in 1885, William Le Baron Jenny built the first modern skyscraper in Chicago. While just 10 stories high, Which seems short by today’s standards, the Home Insurance Company Building was the first structure to have an internal steel skeleton bear all of its weight. From that point on, tall buildings began to soar into the air, scraping the sky. Just 30 years after the first skyscraper was built, buildings were erected that reached 60 stories high.

A bicycle is a simple device that increases the power that you have in the muscles of your legs, taking you faster and farther than you could ever run. When you push the pedals of your bike around once, the pedal sprocket—the wheel with teeth to which the pedals are attached—goes around once, too. But it pulls a chain along, one that is connected to a much smaller sprocket (with fewer teeth to grip each link of the chain) in the center of your bike’s rear wheel. This smaller sprocket moves around a number of times for each single turn of your pedals, moving your bike wheels a lot faster than you’re moving your feet! Some bicycles have several “speeds,” which means that they have a number of gears (called derailleurs) that vary the rate at which the wheels turn. These extra sprockets are located at the pedals and rear wheel of a bike, where levers move the driving chain sideways, from one to another.

A special spring system keeps the chain tight when it changes from a larger to a smaller sprocket. Although you might think that a rider would always want the wheels of his or her bike to move as fast as possible for each pedal turn, that is not always the case. When going uphill, for instance, a rider can get more force out of a wheel that turns fewer times, making the task easier.