Tuesday, April 24. 2018What is Photosynthesis?
Photosynthesis is the process by which green plants make food for themselves and indirectly, for all animals, including human beings. In photosynthesis plants combine water and salts in the soil, and carbon dioxide in the air to build up organic compounds, such as sugar starch and proteins. To do this they use the energy of sun light, which is absorbed with the help of the green dye in their leaves called chlorophyll. This process of manufacturing food from what they absorb through their roots and leaves make green plants the primary food producers in the world. All animals draw their nourishment from them, either by feeding on plants themselves or by eating other animals that do so. During photosynthesis, which takes place only in daylight, excess oxygen is produced and released into the atmosphere for animals to breathe. After the Second World War, the American scientist Melvin Calvin wrote a book about how plants capture the carbon dioxide in the atmosphere. In 1961 he received the Nobel Prize in chemistry in recognition of his work. Picture credit: google Tuesday, April 24. 2018Why are vampire bats dangerous?
Vampire bats are dangerous because they carry rabies and other diseases and infect their victims as they suck the blood which is their only food. Vampire bats (Desmodontidae) are found only in South and Central America. They have extremely sharp teeth and pierce the skin of their prey so gently that the victim does not awaken. Blood is drawn into the mouth by the almost tubular tongue and the vampire bat’s whole digestive system is specially adapted for his diet of blood. Picture credit: google Tuesday, April 24. 2018Where would you find a red Giant?
You would find a Red Giant on the Sierra Nevada Mountains of California in North America. It is a huge redwood tree, called a giant sequoia. These trees, members of the conifer family, are the largest in the world and grow to a height of 300 feet. They have a very hard, reddish brown wood and a thick, very rough bark. The giant sequoias were believed to be the oldest living things in the world. The ring marks on the stumps of the oldest trunks have been carefully counted and it is now known that some of the biggest are about 4,000 years. Many of these trees were cut down for their timber, which is resistant to attacks by fungus, and termites and other insects. To preserve the remaining groves of these huge redwoods, a reservation called the Sequoia National park was set up in 1890. The largest tree there is 272 feet high and has a circumference at the base of its trunk of 101(1/2) feet. Its weight has been estimated to be over 6,000 tons. Some of the other trees are taller but do not have such large trunks. A tunnel has been cut through the base of one of these giant trees which is big enough to drive a car through. Picture credit: google |
|
