Question

Which is true regarding all X-linked disorders?

Group of answer choices

they are caused by mutations of the X chromosome

they are linked to an unknown chromosome

they are disorders that affect only women

they result in a longer lifespan

Answer 1

they are caused by mutations of the X chromosome

Step-by-step explanation:

Answer 2

They are caused by mutation of the X chromosome.

Step-by-step explanation:

• In an XY-chromosomal system of sex determination, Both X and Y- chromosomes are Sex chromosome.
• Genes on sex chromosome are called sex linked genes.
• Sex linked genes are referred to as X-linked while Y-linked genes are the ones located only on the Y-chromosome.
• The genes located in on Y chromosome are holandric.

• Human females are homozygous for X chromosome while Human males are hemizygous i.e. they have only one X-chromosome and another Y chromosome.
• Disorders caused due to the mutation in the X chromosome are called X- linked disorders. Some examples are Hemophilia, Fragile X-syndrome etc.
• Sex lionked disorders can be X-linked Dominant disorder or X- linked Recessive disorder.
• The Dominant disorders are present in every generation, and affected males come from affected mothers. Daughters of affected fathers are always affected but sons of such father are not affected.
• The recessive disorders are more common in Males and these males come from affected mothers or carrier mothers. The affected females come from affected father and an affected or carrier mother.