Cytokinins are defined as compounds that have biological activities similar to those of trans-zeatin. These activities include the ability to do the following:

a) Induce cell division in callus cells in the presence of an auxin

b) Promote bud or root formation from callus cultures when in the appropriate molar ratios to auxin

c) promote senescence of leaves

d) Promote expansion of dicot cotyledons

Which one of the following activities are incorrect?

#Question id: 2574

#Unit 2. Cellular Organization

Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely ________.

#Question id: 2575

#Unit 2. Cellular Organization

NMR studies of the pectin molecules indicate that, which one is not true for pectin ?

#Question id: 2576

#Unit 2. Cellular Organization

What effect will addition of AMP-PNP have on axonal transport?

#Question id: 2577

#Unit 2. Cellular Organization

Which of the following occur(s) during prophase?

a. Kinetochores capture microtubule (+) ends.

b. Chromosomes move poleward.

c. Chromosomes align on the spindle equator.

d. Centrosomes separate and the spindle begins to form.

e. Chromosome condensation begins.

#Question id: 2578

#Unit 2. Cellular Organization

Following statements are regarding to proteins which involve actin filament assembly.

A. To nucleate the assembly of branched actin, Arp2/3 needs to be activated by interacting with a nucleation promoting factor (NPF), in addition to associating with the side of a pre-existing actin filament.

B. The NPF WASp is inactive due to an intramolecular interaction that masks the WCA domain.

C. Two NPFs each bind an actin subunit at their WH2 domains, and together, they activate the Arp2/3 complex through its interaction with their connector and acidic domains.

D. The NPF WASp is activated by a coincidence detection mechanism by which intramolecular interaction in WASp is relieved, allowing the W domain to bind actin and the acidic A domain to activate the Arp2/3 complex.

Which of the following statements represents regulation of the Arp2/3 complex by NPF?

#Question id: 2579

#Unit 2. Cellular Organization

Match the following proteins (Column I) with their functions (Column II) during cell organization and movement.

Which of the following is correct?