Sunday, July 27, 2008

WHERE DID PLANTS COME FROM?



  • Millions of years ago, tiny specks of protoplasm(name for the living material found in both plants and animals) appeared on the earth.

  • They developed a kind of green colouring matter known as chlorophyll that enabled them to make food from substances in air, water and soil.

  • The early green plants had only one cell, but they later formed groups of cells.

  • Spores are little dusklike cells something like seeds, but containing no stored food in them as seeds do.

  • Types of plants with seeds:
    1.Those with naked seeds
    2.Those with protected seeds

  • Types of plants:
    1.Algae – descendents of plants that stay in water.
    2.Fungi – non-green plants that develop food without the use of chlorophyll.
    3.Mosses & Ferns – evolved from algae that developed little leaves with an outer skin covering, as protection against drying.

WHO INVENTED THE HELICOPTER?


Leonardo da Vinci made drawings for a gigantic screwlike helicopter in about A.D.1500 but could not build one because he had no motor to drive it. In 1940, Igor Sikorsky showed his first practical helicopter and it was delivered to the United States Army in 1942.

Saturday, July 26, 2008

What Is Botany?



  • Obtained from Greek word meaning “herb”.

  • Defined as study of plant life dealt mainly with plants as food.

  • Branches of Botany:
    a) Plant Anatomy – deals with the structure of plants and how they are related.
    b) Ecology – deals with distribution of plants throughout the world.
    c) Paleobotany – works out plant evolution for evidence of fossil remains.
    d) Plant Physiology – studies the way plants breathe and make food.
    e) Plant Pathology – concerned with study of plant diseases.