2 Determine whether each of these statements is true or fals

2. Determine whether each of these statements is true or false and then explain why? a) Cadherins promote cell-cell interactions by binding to cadherin molecules of the same or closely related subtype on adjacent cells. b) Although cadherins and Ig family members are frequently expressed on the same cells, the adhesions mediated by Ig molecules are much stronger and thus, are largely responsible for holding cells together. c) Tight junctions perform two distinct functions: they seal the space between cells to restrict paracellular flow and they fence off plasma membrane domains to prevent the mixing of apical and basolateral membrane proteins. d) The extracellular matrix is a relatively inert scaffolding that stabilizes the structure of tissues. e) A sheet of basal lamina underlies all epithelia.

Solution

a) True

Reason:Cadherins are transmembrane proteins that function in cell adhesion of adjacent cell in a tissue.

b) True

Reason:The above statement is true with regards to cadherins and they help to segregate cells into tissues thus maintaining tissue integrity.

c) True

Reason:The tight junction proteins form a barrier that prevents the flow of molecules between cells.It also prevents the movement of molecules such as proteins and lipids from the apical domain to the basolateral domain of a cell and vice versa.

d) False

Reason: Extracellualar matrix is dynamic in nature.

e) True

Reason: Basal lamina is present underneath of all epithelial cells.It