Sex chromosome, either of a pair of chromosomes that determine whether an individual is male or female. The sex chromosomes of human beings and other mammals are designated by scientists as X and Y. In humans the sex chromosomes comprise one pair of the total of 23 pairs of chromosomes. The constricted region of linear chromosomes is known as the centromere. Although this constriction is called the centromere, it usually is not located exactly in the center of the chromosome and, in some cases, is located almost at the chromosome's end.
An allosome (also referred to as a sex chromosome, heterotypical chromosome, heterochromosome, or idiochromosome) is a chromosome that differs from an ordinary autosome in form, size, and behavior. The human sex chromosomes, a typical pair of mammal allosomes, determine the sex of an individual created in sexual reproduction. Sex Chromosomes. The nuclei of human cells contain 22 autosomes and 2 sex chromosomes. In females, the sex chromosomes are the 2 X chromosomes.Males have one X chromosome and one Y chromosome.The presence of the Y chromosome is decisive for unleashing the developmental program that leads to a baby boy.
The XY sex-determination system is the sex-determination system found in humans, most other mammals, some insects (), some snakes, and some plants ().In this system, the sex of an individual is determined by a pair of sex chromosomes.Females typically have two of the same kind of sex chromosome (XX), and are called the homogametic sex.Males typically have two different kinds of sex . Aug 11, 2019 · Chromosomes are long segments of genes that carry hereditary information. They are composed of DNA and proteins and are located within the nucleus of our cells. Chromosomes determine everything from hair color and eye color to sex. Whether you are a male or female depends on the presence or absence of certain chromosomes.