Problem: Consider a tissue made of symmetrically dividing cells that are in a dynamic balance of proliferation and death.
Which of the following scenarios could potentially create one bistable situation where two different non-zero population sizes could be stably maintained? Suppose that the action of each factor can be described by a Hill function. (circle all that apply):
i.) The cells secrete a factor which stimulates their proliferation
ii.) The cells secrete a factor which stimulates their proliferation, and another factor which inhibits death
iii.) The cells secrete a factor which stimulates their proliferation, but their proliferation is limited by contact inhibition
iv.) The cells secrete a factor which inhibits death
v.) The cells secrete a factor which promotes death
vi.) The cells secrete a factor which stimulates their proliferation, and another factor which promotes death
vii.) The cells secrete a factor which inhibits death, but their proliferation is limited by contact inhibition