In this article we will discuss about the evolution of stelar forms in vascular plants. The well known genus Rhynia represents the simplest kind of vascular plant. It is rootless, leafless and the axis is dichotomously branched. A stele runs through the centre of stem. The cells in the very centre of stele consist of tracheids only and this xylem [...]
In this article we will discuss about:- 1. History of Plant Breeding 2. Origin and Evolution of Crop Plants 3. Scope and Objectives. History of Plant Breeding: The process of plant breeding is assumed to be initiated nearly 7000 years ago with the beginning of human civilization. Bringing a wild species under human management as the source of food which [...]
The process of evolution of different species starting from a point in an geographical area and finally radiating to other areas of geography is called adaptive radiation. Examples of adaptive radiation are: 1. Darwin's Finches: Darwin observed an amazing diversity of creature in Galapagos Islands. They represented one of the best examples of adaptive radiation. Of all the varieties of [...]