Charateristics in an organism is based on the combination of traits that they carry.

Traits are inherited, but the traits expression can be due to the interaction with the environment.

EX: lack of color in grass that is not exposed to sunlight, even though the genes have the components, and instructions to make green pigment, it won't due to the outside environment. The fur in shaven Himalayan hare at cold temperatures., if the fur of the hare has an ice pack on it black hair will grow back instead of white.

Body cells can be very different from each other, even though they all come from one cell, stem cell, and all have identical genetic instructions. The instructions that are expressed in the given part of the body is due to the environment in that region.

Bad health habits can also have bad effects on the development and expression of genes and this can result in disease or death. Such as emphases and smoking.