In this article we will discuss about the meaning of transposable elements. The chromosomes of E. coli and other prokaryotes contain discrete moveable segments of DNA called transposable elements, which can be translocated to other locations. Such DNA sequences can move from one position on a chromosome to another, and from one DNA molecule to another. They are detected when [...]
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 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 [...]