Question

Inheritance like incomplete dominance and co-dominance are deviations from Mendel’s law of dominance. Elaborate on the mentioned deviations with the help of examples. [5 marks]

Answer 1

Mendel’s law of dominance states that when characters are controlled by a dissimilar pair of factors, one member of the pair called the dominant pair dominates the other called the recessive. [1 mark]

Incomplete or partial dominance is the phenomenon in which none of the two alleles (factors) of a gene is dominant or recessive over each other When both of them are present together, a new phenotype is formed. The new phenotype
expressed is a mixture of both the phenotypes of its homozygous parents. [1 mark]
Example:

Pink flower colour is in contrast to the red colour which was expected according to Mendel’s principles of inheritance. [1 mark]

In codominance, both the alleles of a gene are expressed simultaneously in the heterozygote. [1 mark]
Example:


[1 mark]