Final answer:
The correct answer is B. to which additional targeting signals direct secretory pathway proteins to organelles is B) ER retention signals and KDEL sequences.
Step-by-step explanation:
The additional targeting signals that direct secretory pathway proteins to specific organelles are ER retention signals and KDEL sequences, nuclear localization signals and nuclear export signals.
mitochondrial import signals and peroxisomal targeting signals. The correct answer to the student's question is B) ER retention signals and KDEL sequences since they are directly related to the endoplasmic .
reticulum, a central organelle in the secretory pathway. Other signals like nuclear localization and export signals are involved in the transport of proteins into and out of the nucleus.
whereas mitochondrial import signals and peroxisomal targeting signals are associated with the transport into mitochondria and peroxisomes, respectively.