Final answer:
Cells indeed regulate gene expression to transcribe genes only when needed, which is true. This regulation saves energy and space as DNA has to be unwound for transcription and translation. Transcription factors play a role in cell-specific gene regulation.
Step-by-step explanation:
It is true that cells regulate gene expression so that each gene will be transcribed only when it is needed. The synthesis of proteins from information encoded in their DNA necessitates precisely timed gene expression. This conservation of resources is crucial because unwinding DNA from its tightly coiled structure to transcribe and translate the DNA requires energy and space.
Different cells regulate gene expression using various transcription factors, which are proteins that influence the binding of RNA polymerase to a specific gene on the DNA molecule. This means that gene expression is a carefully controlled process that, when disrupted, can contribute to diseases such as cancer. Whether in simple unicellular organisms or complex multicellular ones, regulating gene expression is essential for cellular function and overall organismal health.