Chromosomes are made up of DNA and Histone

Introduction:
Chromosomes are thread-like structures found in the nucleus of cells. They carry genetic information in the form of genes. Each species has a specific number of chromosomes, and humans have 46 chromosomes, arranged in 23 pairs. Chromosomes are composed of DNA (deoxyribonucleic acid) and proteins called histones.

DNA:
DNA is a long, double-stranded molecule that carries the genetic instructions for the development, functioning, and reproduction of all living organisms. It is made up of four nucleotide bases - adenine (A), thymine (T), cytosine (C), and guanine (G). These bases pair together in a specific manner (A with T, and C with G), forming the famous double helix structure. DNA is responsible for storing and transmitting genetic information from one generation to the next.

Histones:
Histones are proteins that play a crucial role in DNA packaging and organization. They are rich in basic amino acids and have a positive charge, which allows them to interact with the negatively charged DNA molecule. Histones are present in the nucleus and act as spools around which DNA is wrapped. They help condense the DNA into a compact and organized structure, allowing it to fit inside the nucleus.

Chromatin and Chromosomes:
The combination of DNA and histones is known as chromatin. Chromatin is the relaxed and less condensed form of DNA that is present during interphase (the non-dividing phase) of the cell cycle. It allows the DNA to be accessible for gene expression and replication. However, during cell division, the chromatin undergoes further condensation and becomes tightly coiled, forming visible chromosomes. This condensation helps in the accurate segregation of genetic material during cell division.

Conclusion:
In conclusion, chromosomes are composed of DNA and histones. DNA carries the genetic information in the form of genes, while histones play a crucial role in packaging and organizing the DNA molecule. Together, DNA and histones form the chromatin, which can further condense into visible chromosomes during cell division. Understanding the composition and structure of chromosomes is fundamental to comprehending the inheritance and functioning of genetic material.