The swim-bladder in fishes and the lungs of tetrapods are closely similar in structure and development. Both these structures are intimately associated with the gut. The lungs of higher vertebrates arise exactly the same way as that of the swim-bladder in fishes. Both develop as outgrowths from the gullet and the glottis occupies exactly the same position. But the exact [...]
Learn about the relationship between Gene and Enzyme. An understanding of the relationship of the gene and the enzyme is crucial for an analysis of the basis of growth and development of an organism. It has been established through varied lines of evidences that genes control all hereditary characters of an organism, which are transmitted from generation to generation. Simultaneously, [...]
In this article we will discuss about the relationship between genetic and cytological crossing over. The exchange of homologous segments of chromatids between homologous chromosomes during meiosis was cytologically demonstrated by Stern in 1931 in D. melanogaster and by Creighton and McClintock in the same year in maize. Stern used stocks of D. melanogaster carrying chromosomal structural changes. These stocks [...]