Final answer:
DNA coils into an X-shaped structure during cell division to ensure each daughter cell receives a complete set of genetic material. This coiled form, known as a chromosome, consists of two identical sister chromatids joined at a centromere. The process is crucial for maintaining the continuity of genetic information.
Step-by-step explanation:
Why Does DNA Coil into an X-shaped Structure?
DNA coils into an X-shaped structure to ensure that, during cell division, each daughter cell receives an identical set of genetic material. This is crucial because it maintains the continuity of genetic information across generations of cells. The DNA is organized into structures called chromosomes, which are composed of DNA and proteins.
During the cell cycle, most of the time DNA exists in a more relaxed state known as chromatin. However, when a cell is preparing to divide, the DNA strands coil more tightly to form visible chromosomes. This allows the chromosomes to be easily separated into two sets during the process of cell division, ensuring that each new cell will have the correct amount of DNA. It's during this process that the structure becomes visibly X-shaped, particularly after DNA replication, because each chromosome then consists of two identical copies, or sister chromatids. These are joined at a region known as the centromere.
Humans typically have 46 chromosomes, 23 inherited from each parent. During cell division, each cell must receive 46 chromosomes to maintain the appropriate genetic information. Thus, the condensation of DNA into chromosomes is a vital process for the proper distribution of genetic material.