Crossing over? That involves the random exchange of chromosomes.
Answer:
the tendency toward a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes.
Discontinuous variation <span> refer to large, conspicuous differences from the parents</span>
This is where individuals fall into a number of distinct categories, and is based on features that cannot be measured across a complete range
continious variation refer to small, indistinct differences from the normal condition.
Milk yield in cows, for example, is determined not only by their genetic make-up but is also significantly affected by environmental factors such as pasture quality and diet, weather, and the comfort of their surroundings