Multipass transmembrane proteins synthesized by ribosomes on the rough endoplasmic reticulum generally have which of the following arrangements of start-transfer  and stop-transfer  signals? multiple...

Multipass transmembrane proteins synthesized by ribosomes on the rough endoplasmic reticulum generally have which of the following arrangements of start-transfer  and stop-transfer  signals?

1. multiple start signals and multiple stop signals (to allow multiple transmembrane regions)


2. multiple start signals, but only one stop signal (to allow only one transmembrane region)


3. only one start signal, but multiple stop signals (to allow only one transmembrane region)


4. only one start signal, and only one stop signal (to allow only one transmembrane region)


5. only one stop signal, and only one start signal (to allow only one transmembrane region)