Question

Under normal conditions, when cells are not in contact with other cells this will signalthem to divide. When cells are too closely packed together they will stop dividing.These are examples of ______________ signals.

A. external
B. chemical
C. internal
D. None of the above

Answer 1

It is an example of external contact. The correct option is A.

Answer 2

A. external
These types of signals are observed when there is a cut on the body. The epidermal cells lose contact with one another and divide faster until they are in contact once again. After they come into contact, division slows down again.