One oak tree produces two kinds of leaves: wide leaves with shallow lobes and narrow leaves with deep lobes. if this variation in leaf shape is based solely on the ecological condition of amount of sunlight exposure and there is no genetic difference between leaves that express either of the two forms, then this is:

Phenotypic plasticity

Explanation:

Phenotypic plasticity is the capacity that many plants have to express different phenotypes (for example, various morphological traits, like the different leaves of the oaks in this example) without a change in their genetic makeup when they are subjected to variations in their environment (like the variations in the sunlight exposure of the example). This plasticity has been linked with their success in expanding over a vast territory with very variable climate. Phenotypic plasticity does not limit itself to morphology. It can also be seen in variations in the anatomy, physiology, reproduction and seedling development among other traits.

i think the answer would be a dominant trait.

in situ hybridization has been widely used for research applications, including clinical cytogenetics, gene mapping, tumor biology and studies of chromosome evolution.