Exam 3 Clicker Questions

A decrease in cell adhesion due to the introduction of an experimental substance to a tissue compromises the structural integrity of the tissue. Which cell junction would MOST likely be affected by this treatment causing a decrease in the strength of the tissue? A. Adherens junctions B. Gap Junctions C.Hemidesosomes D. Tight Junctions.

A, Adherens Junctions. Of the choices adherens junctions contribute the most to the overall structural integrity of a tissue. Desmosomes also contribute significantly to tissue strength.

In order for a tumor to metastasize, which of the following would you expect to happen? A. A decrease in cadherin expression and an increase of integrin expression. B. An increase of cadherin expression and a decrease in integrin expression. C. An increase in both cadherin and integrin expression. D. A decrease in both cadherin and integrin expression.

A. A decrease in cadherin expression and an increase of integrin expression The decrease in cadherins allows the tumor cells to separate from the tumor. The increase in integrins allows them to interact with and pass through the basal lamina to reach the bloodstream begin a new tumor elsewhere.

If a mutation occurred in the cadherin gene so that cytoplasmic domain no longer attached to the cytoskeleton, which of the following would occur? A. Cadherins in desmosomes would no longer be bound to intermediate filaments. B. Cadherins in adherens junctions would no longer be attached to microtubules. C. Cadherins in hemidesmosomes would no longer be anchored to intermediate filaments. D. Cadherins in desmosomes would no longer be bound to microfilaments. E. Cadherins in hemidesmosomes would no longer be attached to microfilaments.

A. Cadherins in desmosomes would no longer be bound to intermediate filaments.

Suppose there is a mutation in a lamin-binding intergrin gene that causes a loss of function in the cytoplasmic domains of the integrin. Which of the following would you expect to observe as a result of this mutation? A. The integrin would function normally because the cytoplasmic domain is not responsible for binding laminin. B. Tissues would weaken because the integrin could no longer associate with microfilaments in adherens junctions. C. The integrin would be unable to signal the cytoplasm when it binds to laminin. D. Cell adhesion to laminin would decrease, but laminin-mediated gene expression would remain the same.

C. The integrin would be unable to signal the cytoplasm when it binds to laminin.

Which one of the following statements about intracellular transport is true? A. Kinesin and myosin move substances along microtubules. B. Kinesin and dynein move substances along microfilaments. C. Myosin and dynein move substances along microfilaments. D. Myosin moves substances along microfilaments.

D. Mysosin moves substances along microfilaments