Final answer:
Integrin is involved in anchoring junctions, specifically in hemidesmosomes and adherens junctions, and acts similarly to a 'superglue' in cell adhesion. The most appropriate type of junction associated with integrin would be an adherens junction.
Step-by-step explanation:
An integrin functions within a specific type of anchoring junction that helps to stabilize epithelial tissues by providing strong and flexible connections. These anchoring junctions include desmosomes, hemidesmosomes, and adherens junctions. Desmosomes and hemidesmosomes are known to employ cadherins and integrins, respectively, to facilitate cell-cell and cell-matrix adhesions. Adherens junctions can use either cadherins or integrins for cell-linking. Since integrins are involved and the context suggests a direct comparison to superglue – an adhesive substance – it would be appropriate to classify the type of junction as either a desmosome, which can be thought of as 'riveting' the cells together, or an adherens junction, which acts to adhere or 'glue' cells to one another or the matrix.
Given this information and the specific function of integrins, the correct answer to the question 'Integrin fits between cells and grips them, what type of junction is it?' would be (b) Tight; sealing if integrin was providing a watertight seal, or (a) Adherens; anchoring if integrin was acting more as a 'superglue'. However, since integrins are mentioned as being part of hemidesmosomes linking cells to the extracellular matrix rather than cadherins which are a part of adherens junctional complexes, the question becomes challenging. In the absence of clarifying context, it's difficult to assign a definitive answer but based on available information, adherens junction seems the more likely context for integrins acting as a cellular 'superglue'.