What is the full form of $PKU$?

Mendelian disorders may be of which type?

$A$ colourblind man has a colourblind sister but a normal brother. What is the phenotype of his parents?

Pedigree analysis plays an important role in genetic disorders.

Match the following symbols used in pedigree analysis with their correct meanings.

Given that $X^h$ is the chromosome with the gene for haemophilia and $X$ is the chromosome with the normal gene. Which of the following individuals will act as a carrier for haemophilia?