Mechanisms of Cell Differentiation, Development (2C) Practice Test

Researchers observe that two daughter cells produced by an asymmetric division show different levels of a fate determinant protein (Det-1). The daughter with higher Det-1 later expresses a lineage marker; the daughter with lower Det-1 does not. Blocking polarized localization of Det-1 before division makes both daughters similar and reduces marker expression overall. Cellular principle assessed: asymmetric segregation of cell fate determinants. Which mechanism best explains the development of different cell types?

A differentiation factor (DF) is expressed at similar mRNA levels in two cell types, but DF protein is high only in Cell Type A. Polysome profiling shows DF mRNA is efficiently translated in Cell Type A but not in Cell Type B. Cellular principle assessed: translational control contributing to cell-type-specific protein expression. Which mechanism is most consistent with these data?