Question

During the embryogenesis, axial mesoderm cells are specialized to express different genes. We identified three group of cells present in close proximity. Among these groups one cell subtype (known as Sub1) have probability of 0.5 to express gene XRA. The other cell subtypes (known as Sub2 and Sub3) have a probability of 0.8 and 0.1 respectively. Suppose that we isolated one of these cell subtypes at random and grow them in the lab to study gene expression patterns. We define two states for gene expression; as the state of success (S) if gene XRA is observed and failure (F) if not.

a) What is the probability (P(S)) of observing gene XRA expression?

b) Given that gene XRA will be expressed every hour. What is probability P(SFS) in the next three hours?

c) Assuming that we observed the sequence of SFF, what is the probability of that we isolated the subtype 2 cells during the embryogenesis?

Answer 1