Answer:
Incomplete dominance
Explanation
Incomplete dominance is a pattern of inheritance in which, offspring from the cross of two parents shows a phenotype that is not like either parent but in between both.
For example: Let us take the example of plant snapdragon and its flowers. We have one plant parent with red flowers and it is homozygous for this trait with genotype RR, the other parent with white flowers and it is also homozygous for the allele of same trait with genotype rr. They both are crossed but the offspring is unlike any of the parents and grows pink color flowers.
Why?
Because no allele could fully express itself in the offspring or no allele was actually dominant on the other and both had their own effect at own place.
See how:
                         RR x rr
Gametes:                r     and     R
                    rr:   Rr :   Rr   :  RR
RR:       Red flowers     25%
Rr:        Pink flowers      50 %
rr:         White flowers    25%
This is the case of co-dominance.
Hope it helps!
