Question

1. The image shows a flower that was produced by crossing a pure red flower with a pure white flower. Which do you think is the dominant petal colour: red or white? Explain.
2. How is the inheritance pattern shown by this flower different from other inheritance patterns you have seen or studied?

Answer 1

1. The image you have shared shows a pattern of inheritance known as codominance. In this example, both alleles are expressed, giving you the white and red phenotype. 
2. This pattern of inheritance is quite different from the ordinary Mendelian genetics where there is one dominant trait that completely covers up the expression of the recessive trait. For example, in "normal" inheritance, if R was red and r was white, RR would be red, Rr would be red and rr would be white. In the picture you shared (codominance), we see the following pattern: RR would be red flowers, Rr would be red and white flowers, and rr would be white flowers. <span />