Question

The pedigree chart shows the inheritance of hemophilia in some of the descendants of Queen Victoria. Which letter points to a family member certain to be heterozygous?

Answer 1

" The pedigree chart of Queen Victoria of England illustrates inheritance of hemophilia"

What happend ?

• Three or four of the children of Queen Victoria and Prince Albert had the hemophilia gene and other are afflicted with hemophilia (disorder in which blood doesn't clot)
• A. Queen Victoria herself was a carrier due to mutation and this passed to her children and when her child got married then in this way the Disorder spread in Europe from England so Queen was a transporter.
• So Hemophilia is a sex - linked recessive disorder which is caused without being in contact.

Explain

Which letter points to a family member certain to be heterozygous ??

• Note :- A Diploid condition in which the alleles at a given position on chromosome are differ from each other are called Heterozygous, Heterozygous always means one of each letter, so we'd use "Tt" (where "T" = tall, & "t" = short)
• only one X chromosome, inherited from the mother, and the Y chromosome all men inherit from the father does not protect the male child from manifesting the disorder
• Queen Victoria was a carrier for x linked recessive heamophilic gene which passes to generations showing more number of heamophilic persons in the pedigree.