This pedigree shows the inheritance of colour blindness or sex-linked trait. Is this trait dominant or recessive? Is the mother of the colourblind girl in the F3 generation colourblind, a carrier or a person with normal colour vision? Explain. [4 MARKS]

Q. In skip generation inheritance of colour blindness, the trait from a colourblind man is passed on to ____________.

Q. A family consists of two parents and their five children and the pedigree chart below shows the inheritance of the trait colour blindness in them. [5 MARKS]



(a) Who is colour blind in the parents - Father or Mother?
(b) How many daughters and how many sons have been born in the family?
(c) What does the child 1 indicate about this trait?
(d) On which chromosome is the gene of this trait located?
(e) Name one other trait in humans which follows the similar pattern of inheritance.

Q. A sex linked recessive gene 'C' produces red green colour blindness in humans. A normal woman whose father was colourblind marries a colourblind man. Of all the girls born to these parents, what percentage is expected to be colour blind?

Q. From the pedigree chart given below, identify if the trait is sex linked dominant or recessive.

Q. A family consists of two parents and their five children and the pedigree chart below shows the inheritance of the trait colour blindness.
Figure

(i) Who is colour blind in the parents - Father or Mother?
(ii) How many daughters and sons have been born in the family?
(iii) What does the child 1 indicate about this trait?
(iv) Complete the depiction of all probabilities of the trait among the children 2-5 in the chart.
(v) On which chromosome is the gene of this trait located?
(vi) Name one other trait in humans which follows the similar mode of inheritance.