Sheena and tina are identical twins who developed from a single zygote and share identical dna. nevertheless, as they develop, differences in physical and psychological characteristics become evident. these differences are due to:
The answer is epigenetic changes in their DNA. These are heritable
changes in gene function that do not involve changes in the DNA sequence. This
occurs through methylation patterns and histone modification on the DNA strand that
may result from external or environmental factors.
