Question

Although the law of independent assortment is generally applicable, when two loci are on the same chromosome the phenotypes of the progeny sometimes do not fit the phenotypes predicted. This is due to__________.

Answer 1

Answer:Variation in single and multiple genes.

Explanation:

This is due to changes in the sequence of nucleotides in the GENE on specific loci located on the chromosomes of the DNA molecule.

The change may be due MUTATION. Therefore the expression of phenotype may be different from Madelia laws of independent assortments of genes, because the genes may be linked together and assort jointly,(linkage), or some genes may not have full dominance over the other(incomplete dominance and codominance). Some alleles of another gene may mask or conceal the expression of other allele

Example of these exceptions to the independent assortments are Incomplete dominance, codominance, sex –linkage, epistasis, complementary genes.

Answer 2

Answer:

Linkage

Explanation:

The existence of two loci on the same chromosome (linkage) increases the chances of the genes on these loci to assort or be inherited together.

The closer the two loci on the chromosome, the higher the chances of the two genes being inherited together and further apart they are, the lower the chances because the two genes are more likely to be separated during recombination.

Hence, if two loci on the same chromosome produce progeny that do not fit the predicted phenotypes according to the law of independent assortment, it means the two loci are linked.

The answer is linkage.