Strawberries can reproduce by means of runners, which are stems that grow horizontally along the ground. At the region of the runner that touches the ground, a new plant develops. Why is the new plant genetically identical to the parent?

The new plants are identical to the mother strawberry plant because they are the result of asexual reproduction, that is, from successive mitosis clones of the mother plant are made. The runners do vegetative reproduction, they make the vegetative reproduction by means of which roots and stems are formed with identical cells to the parent.