Which of the following explains the fact that animals that differ greatly in complexity can have similar numbers of genes?

Each organism functions and is based on the structure of their genes which shapes their genotype, the traits of the genes and the phenotype, the external traits and characteristics. Hence, animals with complex structures and even simple ones has the similar fundamental component - genes. Genes, however, can vary in distinct number of ways. In complex organisms they may have the sophisticated structures but the genes that holds those basic structure remains identical hence same number of genes.