In this article we will discuss about the chromosomal theory of inheritance. The chromosomes as well as genes occur in pairs. The two alleles of a gene pair are located on homologous sites on homologous chromosomes. According to this theory: (i) All hereditary characters are carried with sperms and egg cells as they provide bridge from one generation to the [...]
Introduction to Telome Theory: It is now widely accepted (on the basis of overwhelming amount of evidence) that the land- dwelling plants evolved from aquatic ancestors. Ail organisms known in the Precambrian, Cambrian and Ordovician periods of Paleozoic Era lived in aquatic environment. The evolutionary conquest of land probably occurred sometimes between the late Cambrian and early Silurian. The concrete [...]
The following points highlight the four main theories of genetic evolution. The theories are: 1. Lamarckism 2. Darwinism 3. Mutation Theory 4. Synthetic Theory. Genetic Evolution: Theory # 1. Lamarckism: This theory was propounded by Jean Baptiste Lamarck (1744-1829), a French biologist, through his numerous writings. There are four postulates of this theory as listed below: i. Living organisms and their [...]