My Science School

          Banana is a popular fruit and an important part of our diet today. It originally belongs to South-East Asia and the Indonesian region where it used to grow wild in the forests. Over the years, proper selection and cultivation of different varieties yielded the ‘edible’ banana. By the beginning of the Christian era it had already become a popular fruit in the Asian and Mediterranean countries. When the Spaniards settled in South America, they planted it there and being a tropical plant, it grew well. 

          The banana tree grows round the year in hot and moist climate. Bananas are picked when they are still green and left to ripen while being transported.

          Banana is a wholesome food. It is made up of water (75%), sugar (20%), proteins (2%), fats (1.5%), cellulose (1%), and other substances (1%). It also contains vitamins such as A, C, B1 and B2. It is quite a nourishing and easily digestible fruit. Half a kilo bananas contains 460 Calories and are more nourishing than any other fruit. A type of flour is also made of dried banana. In American and Asian kitchens bananas are used uncooked in salads and with ice creams. In Africa people thatch roofs of their huts with the banana leaves. 

          The plant yields a kind of fibre which is used to make ropes.

          There are over 200 varieties of banana belonging to about 30 species. They are never grown from the seed but are produced by planting of rhizome pieces. The new plants grow up amazingly fast from the buds. Its height varies between 5 to 30 ft. Each plant has about 10 large leaves and bears a single bunch of fruit. The banana leaves are about 6 to 7 ft. long and 1 to 2 ft. wide.

          Today, the United States is the greatest buyer of bananas, consuming more than 60 million bunches every year. 

          Man has been using garlic since ancient times to add flavour to food. Garlic has a powerful smell and a pungent taste. The Roman soldiers believed that it helped them in being more courageous and stronger so they made it a point to include it in their regular diet. In the Middle Ages garlic was eaten as a defence against the plague. It was also worn on the body to ward off evil spirits.

          It is only a few years ago that man discovered its medicinal importance. Its bulb contains an antibiotic called allium.

          It has antiseptic properties and is used for curing intestinal disorders. It is highly effective in controlling high blood pressure. It is also being used as an effective remedy for heart ailments and cough.

          Some people crush it and rub it on the skin as a cure against insect bites and stings. Some people make syrup out of it and drink it to cure cold. Gardeners put garlic in the soil around peach trees, to discourage borer from entering and damaging the trees.

          Garlic plant is native to Europe and Asia but it also grows wild in Italy and Southern France. Garlic produces two types of bulbs or bulbets. The aerial bulbets produced on the flower stalk are used as seeds to new plants. It is grown as an annual crop. The underground bulbs, called cloves, are the one sold in shops. They are formed at the base of the plant much like an onion. One bulb encloses up to 20 bulbets. Garlic contains about 0.1% essential oil, the principal components of which are diallyl disulfide, diallyl trisul-fide and allyl propyl disulfide.

          All living beings breathe in order to survive. In the process of breathing they inhale oxygen and exhale carbon dioxide. Oxygen combines with hydrocarbons to produce energy and carbon dioxide.

          Plants are living beings and they also breathe to survive. The only difference between animals and plants, in this regard, is that while the animals inhale oxygen and exhale carbon dioxide, the plants inhale carbon dioxide and exhale oxygen during the day and inhale oxygen and exhale carbon dioxide at night.

          The leaves of plants take in carbon dioxide from the air during the day. A green substance called chlorophyll, that is present in the leaves, converts it into sugar and water. This process is known as ‘photosynthesis’ and it takes place only in the presence of sunlight. The oxygen produced in this process is discharged into the atmosphere and sugar is used up as food by the plants. This sugar gets converted into carbohydrates, carbonic acid and vitamins.

          During the night, when there is no sunlight, the process of photosynthesis comes to an end, during this period plants make use of some part of the sugar produced in the daytime. They take in oxygen from the atmosphere and give out carbon dioxide that is why it is not advisable to sleep under a tree in the night.