Genes are segments of deoxyribonucleic acid DNA that contain the code for a specific protein that functions in one or more types of cells in the body. Chromosomes are made of a very long strand of DNA and contain many genes hundreds to thousands. Except for certain cells for example, sperm and egg cells , every human cell contains 23 pairs of chromosomes. There are 22 pairs of nonsex autosomal chromosomes and one pair of sex chromosomes, for a total of 46 chromosomes.
Sex chromosomes & X-linked inheritance (article) | Khan Academy
What are autosomal traits? And just what are sex-linked traits? In order to understand how the two are different, it is really important to understand what the words autosomal and sex-linked are. A genotype is the entire collection of the genes a person carries—the entire heritable identity that controls everything, from regulating metabolism processes to protein expression. On the other hand, it can also refer to one or a set of genes or a combination of alleles or haplotypes, which are groups of genes that are inherited together carried by an individual. Genotype examples are the different alleles that code for specific features, or phenotypes, of an individual such as hair color brown vs.
The following will give you information about what X linked inheritance means and how X linked conditions are inherited. To understand X linked inheritance, it is first helpful to know about genes and chromosomes. Our bodies are made up of millions of cells.
In humans, there are hundreds of genes located on the X chromosome that have no counterpart on the Y chromosome. The traits governed by these genes thus show sex-linked inheritance. This type of inheritance has certain unique characteristics, which include the following: 1 There is no male-to-male father-to-son transmission, since sons will, by definition, inherit the Y rather than the X chromosome.