its not inactive
X-inactivation typically occurs in individuals with Klinefelter syndrome, which is characterized by having an extra X chromosome (XXY). However, the extra X chromosome in Klinefelter syndrome may not undergo inactivation completely, leading to some cells expressing genes from the additional X chromosome. This can result in a variety of symptoms and characteristics associated with Klinefelter syndrome.
X chromosome inactivation
X-chromosome inactivation is a normal process in female mammals where one of the two X chromosomes is randomly inactivated in each cell during embryonic development. The inactivated X chromosome forms a structure called a Barr body, which helps to equalize gene expression between males (XY) and females (XX). This process ensures that both males and females have a similar dosage of X-linked genes.
this is the process by which one of the two copies of the X-chromosomes present in female animals is inactivated
X chromosome inactivation happens in female mammals.
Male carry XY genotype whereas female has XX. Two copies of X chromosome means, there is a great chance of potentially toxic double dose of X-linked genes. It is known that 1000s of genes responsible for growth and cell viability are there in X chromosomes.To avoid the over production of these genes in female (where 2 X chromosomes present), there is a mechanism evolved that transcriptionally control or silence on of these two X chromosome.http://www.nature.com/scitable/topicpage/x-chromosome-x-inactivation-323
X chromosome inactivation is a process that occurs in female mammals where one of the X chromosomes in each cell is randomly inactivated. This ensures that both males and females have similar levels of X chromosome gene products. The inactivated X chromosome condenses into a structure called a Barr body.
Since one X chromosome in each cell is randomly inactivated at some point during development, a woman heterozygous for hypertrichosis would have varying regions of patchy hair if the alleles responsible for the trait were located on the X chromosome. Variation would look similar to the varied tortoise shell coat color pattern on female cats, where the presence of yellow and black (red and gold/blue and cream) is controlled by X chromosome inactivation.
X-inactivation is necessary in individuals with two X chromosomes to ensure that only one X chromosome is active in each cell. This process helps to balance gene expression between the two X chromosomes and prevent an imbalance of gene dosage, which could lead to developmental abnormalities and disorders.
The human male has both an X and Y chromosome which determines the sex of an offspring. Female only have the X chromosome.
The X chromosome is one of the two sex chromosomes in humans (the other is the Y chromosome). The sex chromosomes form one of the 23 pairs of human chromosomes in each cell. The X chromosome spans about 155 million DNA building blocks (base pairs) and represents approximately 5 percent of the total DNA in cells. Each person normally has one pair of sex chromosomes in each cell. Females have two X chromosomes, while males have one X and one Y chromosome. Early in embryonic development in females, one of the two X chromosomes is randomly and permanently inactivated in cells other than egg cells. This phenomenon is called X-inactivation or Lyonization. X-inactivation ensures that females, like males, have one functional copy of the X chromosome in each body cell. Because X-inactivation is random, in normal females the X chromosome inherited from the mother is active in some cells, and the X chromosome inherited from the father is active in other cells. Some genes on the X chromosome escape X-inactivation. Many of these genes are located at the ends of each arm of the X chromosome in areas known as the pseudoautosomal regions. Although many genes are unique to the X chromosome, genes in the pseudoautosomal regions are present on both sex chromosomes. As a result, men and women each have two functional copies of these genes. Many genes in the pseudoautosomal regions are essential for normal development. Identifying genes on each chromosome is an active area of genetic research. Because researchers use different approaches to predict the number of genes on each chromosome, the estimated number of genes varies. The X chromosome likely contains between 900 and 1,400 genes. These genes perform a variety of different roles in the body. (Note: So I believe your answer will be 46; 23x2)
X inactivation is an exception to Mendel's laws because it involves the inactivation of one of the two X chromosomes in females, allowing for dosage compensation between males and females. This process results in the random silencing of one X chromosome and the formation of Barr bodies, altering the expected patterns of inheritance predicted by Mendel's laws.