The pattern of inheritance suggested by the graph is A. incomplete dominance. Therefore , A. incomplete dominance is correct.
The graph shows a range of phenotypes for reddish pigment in wheat kernels, with some offspring having intermediate shades of red between the two parental phenotypes.
This is a characteristic of incomplete dominance, where neither allele fully masks the other, resulting in a blending of the two traits.
Multiple alleles and codominance can also result in a range of phenotypes, but the way the phenotypes are distributed in the graph is not consistent with these patterns.
In multiple alleles, there would be more than two distinct phenotypes, and in codominance, the intermediate phenotype would be as common as the parental phenotypes.
Polygenic inheritance is a more complex pattern that involves multiple genes interacting to influence a single trait.
It is not likely to be the case here, as the graph shows a simple pattern of inheritance with two parental phenotypes and an intermediate offspring phenotype.
Therefore, based on the distribution of phenotypes in the graph, incomplete dominance is the most likely pattern of inheritance for reddish pigment in wheat kernels.
Here are some additional details about the other options:
Multiple alleles: This occurs when a gene has more than two possible alleles.
For example, if the gene for reddish pigment in wheat kernels had three alleles (red, white, and pink), then there could be more than two distinct phenotypes in the offspring.
Codominance: This occurs when both alleles of a gene are fully expressed in the offspring, resulting in a distinct phenotype that is different from either parent.
For example, if the gene for reddish pigment in wheat kernels had two codominant alleles (red and white), then the offspring would have a pink phenotype.
Polygenic inheritance: This occurs when multiple genes interact to influence a single trait.
The phenotype is determined by the combined effect of all the genes involved. For example, skin color in humans is a polygenic trait.