Final answer:
Symmetry in organisms is best summarized as being controlled by both genetic and environmental factors. Genes play a fundamental role in determining symmetry during the embryonic stage, but environmental influences also contribute to the final phenotype.
Step-by-step explanation:
The factors controlling symmetry in organisms are controlled by multiple factors. The most accurate choice is c) Both genetic and environmental factors. Axis formation and the determination of body symmetry occur at the genetic level and are articulated during the blastula stage of embryonic development. However, environmental factors also play a crucial role in an organism's development, potentially influencing phenotype.
For instance, genetic variance within a population can lead to differences in symmetry, and this variance is influenced by genetic structure. Moreover, environmental aspects like diet composition can also influence population variance, contributing to changes in symmetry. This suggests that genetic and environmental factors together dictate the symmetry of organisms.
Furthermore, it's important to understand that somatic cells in an organism have the same genetic content, but not all genes are expressed in every cell. The control of gene expression culminates in the development of a complex organism with specific features, including body symmetry.