Cell Junctions MCQ - Practice Questions with Answers

Epithelial cells are connected by the intercellular junctions which are as follows
1. Tight junctions:  Plasma membranes of two epithelial cells in the apical parts are fused together to form tight junctions. These check the flow of materials between the cells.  
2.  Gap junctions: These are responsible for the exchange of chemicals between adjacent cells.
3. Adhering junctions: These act like cement to keep neighbouring cells together. These are of three types
      (a). Zonula adherens: These are dense plaque-like structure towards the cytoplasmic side of each plasma membrane from which fine microfilaments are extended into the cytoplasm. 
      (b). Desmosomes: These are also plaque-like thicker and stronger junctions with microfilaments of keratin protein. These microfilaments are called tonofibrils. This anchor the cells.
     (c). Hemidesmosome: These are similar to desmosomes, but the thickening of the cell membrane is seen on one side only. These join epithelial cells to the basal lamina.