Answer:
Alleles.
Explanation:
Genes may be defined as the functional unit of the DNA. The genes are transmitted into the next generation and they code for the particular protein product that determines the trait of the organism.
Genes exist in two forms known as alleles. Alleles are the alternative forms of gene present on the same chromosome. For example the gene responsible for tallness has two alternative forms of alleles are T and t. The different form of gene is allele.
Thus, the correct answer is option (C).
