Question

Which of the following is not a characteristic of normal cells?

a) They grow as a monolayer.
b) They grow as multiple layers.
c) They undergo a limited number of divisions and then die.
d) They stick tightly to the surface of glass culture dishes.

Answer 1

The characteristic not typical of normal cells is that they grow as multiple layers. Normal cells grow as a monolayer, exhibiting contact inhibition and requiring solid support for attachment and growth.

Step-by-step explanation:

The characteristic that is not typical of normal cells is that they grow as multiple layers; therefore, the correct answer is (b) They grow as multiple layers. Normal cells typically grow as a monolayer and exhibit contact inhibition, which means they stop dividing when they come into contact with each other or cover the surface they are growing on. In contrast, cancer cells lack contact inhibition and have the ability to grow in multiple layers because they do not stop dividing upon making contact with each other. Normal cells also undergo a limited number of divisions before they stop growing due to built-in senescence mechanisms or lack of proper culture media. Furthermore, normal cells require a solid support for growth, such as glass or plastic, and adhere strongly to such surfaces.