Question

A son and daughter were born colour blind .The father was colour blind but mother had normal colour vision .Draw a selfexplanatory cross to show this

Answer 1

Answer:

In this case father is colour blind showing its phenotype. While, mother is phenotypically normal, but carries an allele of colour blindness.

Explanation:

• Here, the father is colour blind (X°Y) whereas mother is a carrier (X°X).
• Thus, 50% son and daughters are colour blind. Kindly, see the above cross.

Answer 2

Answer:

Self-explanatory cross

Explanation:

Why son and daughter born color blind?

• Here, the father is color blind and the mother has normal vision.
• The possible self explanatory cross : find attached photo.

From the cross we can say that mother is carrier and father is color blind which is responsible for color blindness in their children.

From cross we can say four type of progenies are possible:

1. Color blind daughter
2. Color blind son
3. Carrier daughter
4. Normal son

Here, color blind father and carrier mother is having  two children - Color blind daughter and son.