If a normal visioned man marries a woman whose father was also colour blind. Then his wife would be carried of this disease if her mother was normal. This trait passed into children but daughters produce by this couple are carrier not the colour blind. 50% of sons would be colour blind.

Incomplete (partial or mosaic) dominance is the phenomenon where none of the two contrasting alleles or factors is dominant. The expression of the character in a hybrid or F₁ individual is intermediate or a fine mixture of the expression of the two factors (as found in homozygous state). Incomplete or mosaic inheritance is not an example of pre-mendelian concept of blending inheritance because the parental types reappear in the F₂ generation. It is however, considered by some workers to be an example of quantitative inheritance where only a single gene pair is involved. F₂ phenotypic ratio is 1 : 2 : 1, similar to genotypic ratio.

(i) Crl incomplete dominance is reported in flowers of Four O’Clock or Mirabilis jalapa and Antirrhinum majus(Snapdragon or Dog flower).

Inheritance of skin colour in human is controlled by three genes, A, B and C which is polygenic inheritance.

Colour blindness in a X-chromosome linked character. So they’ll be having all colour blind sons and carrier daughters.

In grasshopper the males lack a Y-sex chromosome and have only an X-chromosome. They produce sperm cells that contain either an X chromosome or no sex chromosome, which is designated as O.

Test cross is the cross of an individual with an individual having recessive phenotype. It is used to determine the genotype of a plant showing the dominant phenotype, that means to determine whether the individual exhibiting dominating characters are homozygous or heterozygous.