Imagine the two situations shown in Figure Q7–2. In cell 1, a transient signal induces the synthesis of protein A, which is a transcription activator that turns on many genes including its own. In cell 2, a transient signal induces the synthesis of protein R, which is a transcription repressor that turns off many genes including its own. In which, if either, of these situations will the descendants of the original cell “remember” that the progenitor cell had experienced the transient signal? Explain your reasoning.

Figure Q7–2

Transcribed Image Text:

(A) CELL 1 transient signal OFF A transcription activator turns on transcription of activator MRNA activator protein turns on its own transcription (B) CELL 2 transient signal OFF R R R repressor protein turns off its own transcription turns on transcription of repressor mRNA repressor transcription