No, what determines a dominant gene is how many copies of that gene exists within the parent. This doesn't mean it will be the most common because of recessive genes. It doesn't matter how many copies a dominant gene has, a recessive gene can still appear in the offspring.
The right answer is The cells are damaged.
Take the example of skin cells.
The skin consists of two tissues:
* the outermost, the epidermis, resting on a vascularized connective tissue,
* the dermis.
In the epidermis, which includes several layers of cells, the outer layer is formed of dead cells that are desquamating and are constantly being replaced from proliferating basal cell cells. So, in normal conditions, the epidermis is in constant renewal.
On the other hand, when accidentally, the upper parts of the epidermis are damaged, for example, a slight abrasion or of a burn, the destroyed portion is regenerated (replaced) thanks to an accelerated proliferation of basal epidermal cells .
Studying cells helps us to construct better medicines and vaccines, which is beneficial to understanding life.
These primates have retained some primitive mammalian anatomical and behavioral traits, such as a strong sense of smell with an associated longer snout, eyes that are positioned more to the sides of the head, a smaller brain, a distinct breeding season and litters of offspring, nocturnal activity and the ability to synthesis vitamin C.