The Y-chromosome is one of the two sex chromosomes in humans, the other being the X-chromosome. It is typically found in males, who have one Y-chromosome and one X-chromosome, while females have two X-chromosomes. The Y-chromosome plays a crucial role in determining male sex characteristics and is responsible for the development of male reproductive organs. In addition to its role in sex determination, the Y-chromosome carries genes that are important for sperm production and male fertility. It is much smaller than the X-chromosome and contains fewer genes, which makes it a subject of interest in studies related to genetics and evolution.