You are designing a cell that will have the ability to increase gene expression through signal transduction in response to oxytocin. What factor will be most important to the success of your project?

the number of oxytocin receptors on the cell surface  

Explanation:

The increase of the number of hormone receptors present on the surface of target cells increases the sensitivity of such cells to the hormone. Oxytocin is a neuropeptide hormone produced by the hypothalamus and released by the posterior pituitary gland. This hormone acts as a neurotransmitter that binds to oxytocin receptors in order to trigger a molecular cascade that finalizes with the activation of the enzyme Phospholipase-C. Oxytocin receptors are found in different types of brain cells including, for example, the amygdala and hippocampus (where oxytocin binds). This hormone acts as a chemical messenger that modulates brain functions associated with the reproductive system (i.e., childbirth and lactation) and human behavior.

a "theory" a suggestion that is not 100 % accurate, or a figure. some people say its a theory because they of all the passed theory's about one subject. it depends sometimes theory might be accurate and sometimes they are.

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).