Segment of DNA which participates in crossing?

Question

Accepted Answer

The correct option is 1: Recon.

The term "recon" refers to the smallest segment of DNA that is capable of undergoing recombination, which is the process of crossing over between homologous chromosomes. During meiosis, genetic recombination ensures genetic diversity by exchanging genetic material between paternal and maternal chromosomes. The recon is essentially the fundamental unit of recombination, signifying the minimal distance along a DNA molecule where such an exchange can occur. This genetic rearrangement is crucial for evolution and the variation observed within species.

The incorrect option is 2: Ciston. The term "cistron" refers to a segment of DNA that codes for a polypeptide chain, essentially a gene. It is the functional unit of a gene and is involved in protein synthesis, not directly in the physical act of crossing over.

The incorrect option is 3: Muton. A "muton" is defined as the smallest unit of DNA that can undergo mutation. While mutations can occur within any segment of DNA, including recons and cistrons, the term muton specifically highlights its capacity for change, not its direct involvement in recombination.

The incorrect option is 4: Operon. An "operon" is a functional unit of DNA containing a cluster of genes under the control of a single promoter. It is primarily found in prokaryotes and regulates gene expression, allowing for coordinated control of related genes. It does not directly describe a segment of DNA that participates in crossing over.