CHAPTER 7 - THE NATURE OF THE GENE AND THE MODE OF GENIC ACTION

Abstract

This chapter discusses the nature of the gene and the mode of genic action. The study of genetical phenomena at the biological level had revealed much concerning the nature of the gene and concerning the ways in which it exerted its influence upon the processes of development. As the principles of heredity appeared the same in those species in which the fertilized ovum developed within the maternal body and in those in which the male and the female gametes were extruded from the parental bodies thereafter to meet and to give rise to new individuals quite independently of the parents, it was concluded that the hereditary units, the genes, were carried in the gametes because these alone constituted the bridge between the generations. The observed facts concerning reciprocal crosses where the F1 individuals had the same phenotype, no matter which way the cross was made, was taken to indicate that, in general, the female and the male gamete contributed equally to the transmission of the genes.