Which statement best describes cancer cells? . a. they grow as a single layer of cells.. b. they cease to reproduce after 20–50 mitotic divisions.. c. they reproduce only when needed to replace missing cells.. d. they are not regulated by contact inhibition..

The statement that best describes cancer cells is option D.

The correct answer is -

D) They are not regulated by contact inhibition.

Explanation:

Cancer cells are the rapidly proliferating cells that divide even without the presence of growth factors. They do not obey the property of contact inhibition (unlike normal cells, which stop dividing when they come in contact with each other).

In other words, cancer cells form disorganized multilayer of cells, which can not be regulated. As a consequence, they can even cross the blood vessels to other body organs ( a process that is called metastatis).

Thus, option D) is the best statement that describes cancer cells.