Which one of the following symbols and its representation, used in human pedigree analysis is correct?

Genes for colour blindness is carried by

$I.$ Abnormal development

$II.$ Father

$III.$ Mother

$IV.$ Autosomes

If a boy's father has haemophilia and his mother has one gene for haemophilia; what is the chance that the boy will inherit the disease

If a man who is colour blind marries a women, who is pure normal for colour vision, the chances of their sons have colour blindness is

Both husband and wife have normal vision though their fathers were colourblind and mothers did not have any gene for colour blindness. The probability of their daughter becoming colourblind is

Given below is a pedigree chart of a family with five children. It shows the inheritance of attached earlobes as opposed to the free ones. The squares represent the male individuals and circles the female individuals Which one of the following conclusions drawn is correct