The system of membrane-lined sacs that forms channels throughout the cytoplasm and whose membrane is...

Explanation

The question is asking about a system of membrane-lined sacs in the cytoplasm with a membrane that is connected to the nuclear membrane. The options to choose from are mitochondrion, ribosomes, endoplasmic reticulum, and Golgi apparatus. The correct answer is option C, which is the endoplasmic reticulum. The endoplasmic reticulum (ER) is a network of flattened sacs and branching tubules that extend throughout the cytoplasm of eukaryotic cells. It is continuous with the nuclear membrane, which surrounds the nucleus, and is composed of two types: rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER). RER is studded with ribosomes on its surface while SER lacks ribosomes. The ER is involved in various cellular processes, including protein synthesis, lipid metabolism, and detoxification. The RER, which has ribosomes attached to its surface, is responsible for the synthesis and modification of proteins that are destined for secretion, membrane insertion, or lysosomal degradation. The SER, on the other hand, is involved in lipid synthesis, hormone synthesis, and detoxification of drugs and toxins. In summary, the correct answer to the question is option C, which is the endoplasmic reticulum. The ER is a system of membrane-lined sacs that forms channels throughout the cytoplasm and whose membrane is continuous with the nuclear membrane. It is involved in various cellular processes, including protein synthesis, lipid metabolism, and detoxification.