A chromosome is a strand of DNA that is encoded with genes. Genes are located on chromosomes. Chromosomes are comprised of a strand of DNA firmly folded over proteins called histones. This makes the DNA minimal and ready to fit inside the cell's core. A quality is a fragment of DNA that encodes for an attribute. Thusly, qualities are situated on chromosomes. On every chromosome is a narrowing point called a centromere, which partitions the chromosome into various areas. Human cells regularly contain 23 sets of chromosomes, or 46 chromosomes all out. An individual acquires 23 chromosomes from each parent. On the off chance that there is an adjustment in the number or structure of chromosomes, it very well may be dangerous. For instance, a few malignant growths are the consequence of divided chromosomes sorted out. Moreover, Down disorder, otherwise called trisomy 21, is the consequence of having an additional duplicate of the twenty-first chromosome. People with trisomy 21 have 47 chromosomes. Morphology of chromosome - Telomere, Chromatids, Centromere, Primary and secondary constrictions. Types of chromosomes metacentric, submetacentric, acrocentric, and telocentric.