A Level Biology Practice Exam

Which biological process involves transport of bacterial cells into a cell?

1. Exocytosis

2. Facilitated diffusion

3. Bulk transport via endocytosis

4. Simple diffusion

The correct answer is: Bulk transport via endocytosis

The process by which bacterial cells are transported into a cell is bulk transport via endocytosis. This method allows eukaryotic cells to engulf large particles or entire cells, such as bacteria, by folding their plasma membrane around the material and forming a vesicle. This is particularly important for immune cells, such as macrophages, which utilize endocytosis to ingest and eliminate pathogens. Endocytosis can be further categorized into phagocytosis, where large particles like bacteria are taken up, and pinocytosis, which concerns the uptake of liquids. The specific mechanism involves the alteration of the cell membrane to create an internal compartment that isolates the ingested material from the cytoplasm, enabling the cell to deal with it effectively. In contrast, the other processes mentioned do not facilitate the transport of bacterial cells into a cell. Exocytosis is the process of expelling materials from a cell, facilitated diffusion involves the passive transport of substances across a membrane via specific proteins without the need for energy, and simple diffusion is a form of passive transport where molecules move directly through the phospholipid bilayer according to their concentration gradient. None of these processes are specifically designed for the uptake of larger particles like whole bacterial cells.