Structural Organisation in Plants and Animals

UNIT TWO

STRUCTURAL ORGANISATION IN PLANTS AND ANIMALS

The description of the diverse forms of life on earth was made only by observation - through naked eyes or later through magnifying lenses and microscopes. This description is mainly of gross structural features, both external and internal. In addition, observable and perceivable living phenomena were also recorded as part of this description. Before experimental biology or more specifically, physiology, was established as a part of biology, naturalists described only biology. Hence, biology remained as a natural history for a long time. The description, by itself, was amazing in terms of detail. While the initial reaction of a student could be boredom, one should keep in mind that the detailed description was utilized in the later day reductionist biology where living processes drew more attention from scientists than the description of life forms and their structure. Hence, this description became meaningful and helpful in framing research questions in physiology or evolutionary biology. In the following chapters of this unit, the structural organisation of plants and animals, including the structural basis of physiological or behavioural phenomena, is described. For convenience, this description of morphological and anatomical features is presented separately for plants and animals.

KATHERINE ESAU was born in Ukraine in eighteen ninety-eight. She studied agriculture in Russia and Germany and received her doctorate in nineteen thirty-one in United States. She reported in her early publications that the curly top virus spreads through a plant via the food-conducting or phloem tissue. Dr. Esau's Plant Anatomy published in nineteen fifty-four took a dynamic, developmental approach designed to enhance one's understanding of plant structure and had an enormous impact worldwide, literally bringing about a revival of the discipline. The Anatomy of Seed Plants by Katherine Esau was published in nineteen sixty. It was referred to as Webster's of plant biology - it is encyclopediac. In nineteen fifty-seven she was elected to the National Academy of Sciences, becoming the sixth woman to receive that honour. In addition to this prestigious award, she received the National Medal of Science from President George Bush in nineteen eighty-nine.

When Katherine Esau died in the year nineteen ninety-seven, Peter Raven, director of Anatomy and Morphology, Missouri Botanical Garden, remembered that she 'absolutely dominated' the field of plant biology even at the age of ninety-nine.

Five point one. The Root Five point two. The Stem Five point three. The Leaf Five point four. The Inflorescence Five point five. The Flower Five point six. The Fruit

Five point eight. Semi-technical Description of a Typical Flowering Plant