Question

50.When mammalian cells are irradiated with UV light, they stop dividing and arrest at a G checkpoint. Place the following events in the order in which they occur.

W. Production of p21

X. DNA damage signals through ATM

Y. Inactivation of cyclin-Cdk complex

Z. Activation of p53

a. W, X, Z, Y

b. X, Z, W, Y

c. Y, X, W, Z

d. Z, W, X, Y

33.Which of the following molecular motors is associated with intermediate filaments?

a.Kinesins

b.Dyneins

c.Myosins

d.Both (a) and (b)

e.There are no motors associated with intermediate filaments.

25.What is the role of the nuclear localization sequence in a nuclear protein?

a.It binds a transport protein that directs the complex to the nucleus.

b.It is a hydrophobic sequence that enables the protein to enter the nuclear membranes.

c.It aids protein unfolding in order for the protein to thread through nuclear pores.

d.It prevents the protein diffusing out of the nucleus via nuclear pores.

26.If you add an N-terminal signal sequence to a soluble cytoplasmic protein it will be directed to the ________ and it will ultimately end up ____________

a.To the endoplasmic reticulum; in the lysosome

b.To the endoplasmic reticulum; secreted from the cell

c.To the endoplasmic reticulum; staying in the Golgi

d.Cytoplasm; in the cytoplasm