Kevin Fahling, age 14, of Peoria, I11., for his question:
WHERE DID THE METRIC SYSTEM COME FROM?
In France late in the 18th century, a formula of measurement called the metric system was invented. Used in the new system as a standard of. length were dimensions related to the earth rather than to the dimensions of a man.
Units in the system are defined so they relate to each other in units of 10, fitting into the decimal system.
There's also a relationship between units of length, volume and mass. Basic unit of length is the meter (about 39.37 inches) with volume based on the cube of a length measure, such as a cubic centimeter. Mass and weight are based on the standard kilogram with temperature measured on the centigrade, or celsius, scale.
Anna Felice, age 10, of Niagara Falls, Ontario, Canada, for her question:
HOW DO BLOSSOMS TURN INTO FRUIT?
Fruit is very important to us since it has high nutritional value. It also gives a vital balance to our daily diets. We should eat some fruit every single day. We can eat it fresh, canned and dried. And we can also enjoy it in liquid form, in ice cream and sherbet and baked into pies, cakes and cookies.
In springtime, flowers break out on fruit trees. We are provided with a delicate display of beauty that is hard to beat in nature.
Then comes the dramatic event that will turn each blossom into a delicious piece of fruit. And this bit of nature's magic is started by bees who handle the chore of pollinating and fertilizing each flower with pollen.
The lower part of the flower's pistil, called the ovary, develops into the fruit. Sometimes tissue that grows from the base of the flower an area which scientists call the receptacle also forms part of the fruit. Each seed grows from a little spot called an ovule, found in the ovary.
Fruit is actually a plant structure that contains seeds. You know, of course, we put such good items as apples, cherries, oranges, melons, pears and peaches into the "fruit" classification. But did you know that the tomato is also a fruit? And, in a scientific sense, such edible plants as pumpkins, squash, cucumbers and eggplants are actually fruits and not vegetables.
A number of fruits, such as bananas, seedless oranges, grapefruit and some grapes, are produced without seeds. But others, like watermelon and cantaloupe, make up for any seed shortage by producing hundreds of them.
Some fruits contain just one seed, such as the avocado, peach, apricot, plum and olive. Most nuts and acorns are also one seeded fruits.
When a flower has many pistils, we have a great many little fruitlets, since the ovary of each pistil produces a small fruit. In this classification is the strawberry. The part of the fruit which we eat is the swollen receptacle of the flower. In the blackberry we have a number of little fruits produced from one flower.
Sometimes a number of small flowers grow so closely together that all of the fruits produced by the mass of flowers grow together as one compound fruit. This happens with the fig, mulberry and the breadfruit.
With fleshy fruits, such as apples, pears, cherries and plums, the skin and the flesh are developed from the wall of the flower's ovary and sometimes also from the base of the flower.