In this article we will discuss about the definition of cistron. The earlier geneticists considered a gene to be the smallest unit (a bead or a chromomere) on a chromosome which could be distinguished as a functional unit, or as a unit of recombination, or as a unit of mutation. It was also believed that crossing over occurred only between [...]
In this article we will discuss about the introduction and intron, exon structure of split genes. Introduction to Split Genes: It has been generally believed that a gene is a continuous, uninterrupted sequence of nucleotides which codes for a single polypeptide chain. Some recent work has shown that this may not always be so. The sequences of some eukaryotic genes [...]
In this article we will discuss about the concept of gene conversion. In eukaryotes reciprocal exchange between loci almost always produces reciprocal recombinants. In Neurospora the linear arrangement of ascospores in the ascus indicates directly which strands have exchanged segments during crossing over. Thus after meiosis in a heterozygote Aa, due to reciprocal exchange the 8 ascospores are arranged in [...]