Chromosomes are crucial structures within eukaryotic cell nuclei, primarily composed of DNA and proteins, playing key roles in cell division, growth, and development. DNA, a double-helix molecule, carries genetic instructions essential for an organism’s functioning and reproduction. This DNA wraps around histone proteins, which help organize and compact it into structural units called nucleosomes, and regulate gene expression. Non-histone proteins further contribute by managing chromatin structure and gene functions, including DNA replication and repair.
Chromatin, the complex of DNA and histone proteins, exists in two forms: euchromatin, which is loosely packed and gene-rich, and heterochromatin, which is tightly packed and generally inactive. Telomeres, repetitive sequences at chromosome ends, protect them from deterioration and fusion, ensuring chromosomal stability during cell division. The centromere, a central constriction of the chromosome, is crucial for proper chromosome segregation during cell division. Together, these components maintain chromosome structure and function, ensuring accurate genetic information transmission and cellular processes.