MCB 252 Final Exam Review

Which part of dynein contacts the Arp1? The stalk The head The stem None of the above

None of the above

γ-TURC plays a role in which of the following processes? Elongation of microtubules Capping of the plus end of microtubules Nucleation of microtubules Elongation of microtubules and capping of the plus end of microtubules All of the above

Nucleation of microtubules

Which of the following proteins is most likely a transmembrane protein? Occludin Zonula Occludins-1 (ZO-1) ZO-2 All of the above

Occludin

Why is the concentration of Ran-GTP higher in the vicinity of the chromosomes than in regions of the cell far from the chromosomes?

Ran-GEX is bound to the chromosome in comparison to Ran-GAP which is distributed throughout the entire cell.

Assume EB-1 is regulated by Ran-GTP signaling in mitosis prior to anaphase. How would you expect Ran-GTP to impact the function of EB-1? (Would Ran-GTP signaling be expected to activate or repress EB-1 function?)

Ran-GTP would activate EB-1 as the role of Ran-GTP is to stabilize and promote growth of microtubules during mitosis, which are both functions of EB-1 as well.

In which of the following time frames do we think that LUCA existed? 1.6 to 2.1 million years ago 3.6 to 4.1 million years ago 5.6 to 6.1 million years ago 3.6 to 4.1 billion years ago 5.6 to 6.1 billion years ago

3.6 to 4.1 billion years ago

You are studying a cell line in in which one cell cycle takes approximately 24 hours. You perform FACS analysis on a population of your dividing cells. Your cells are growing asynchronously meaning different cells are in different stages of the cell cycle. Your FACS analysis indicates that 1/3 of your cells have a DNA content of 2n. How long is the G1 phase in these cells?

8 hours

Which type of junction effectively connects the actin cytoskeleton of one cell to the intermediate filament cytoskeleton of an adjacent cell?

Adherens junction

Which of the following techniques was used in Lee Hartwell's primary screen for cdc mutants? Plating for single cells Mutagenizing cells Replica plating Plating for single cells and replica plating All of the above

All of the above

You are studying a particular protein we'll call YFP (for Your Favorite Protein). You hypothesize that YFP binds tightly to other proteins in the cell and wish to identify those proteins. Which technique discussed in lecture will most directly allow you to achieve your goal?

Co-immunoprecipitation experiment

Which one of the following terms most specifically describes the type of allele of the CDC genes that Lee Hartwell isolated in order to study the cell cycle in the bakers/brewers yeast S. cerevisiae? Loss of Function Recessive Gain of Function Dominant Conditional/temperature sensitive

Conditional/temperature sensitive

Which type of tissue described in lecture is involved in support, connecting body parts, and cushioning?

Connective tissue

Which family of protein are found in (and make up) GAP junctions?

Connexins

Which type of junction effectively connects the intermediate filament cytoskeleton of one cell to the intermediate filament cytoskeleton of an adjacent cell?

Desmosome

In lecture we discussed an experiment that helped identify the region in cadherins which is significant for their binding to specific cadherins. What was this experiment?

Domain swapping experiment

Which of the following techniques was used in the experiment we discussed in lecture that determined the step size of a dynein motor protein? An optical trap Fusion of dynein to GFP A sliding filament assay X-ray crystallography Electron microscopy

Electron microscopy

What specific type of experiment demonstrated that cadherins were sufficient to mediate cell-cell adhesion?

Expression of a cadherin gene in cells that do not normally adhere to each other (e.g. fibroblasts)

T/F As discussed in lecture, microtubules that are anchored in a centrosome are nucleated by and are extensions of the microtubules that comprise the centrioles.

False

T/F As discussed in lecture, within a centrosome the two centrioles are identical to each other.

False

T/F Kinesins are minus end directed motors proteins.

False

Which type of junction effectively connects the actin cytoskeleton of one cell to the extra-cellular matrix (ECM)?

Focal adhesion

MPF drives (or regulates) which transition in the cell cycle?

G2 → M

This experiment involves a type of tissue culture cell that normally has very little or no adhesive properties. You express a single type of cadherin in these cells. In one set of cells you express a higher level of cahdherin and label those cells with one color. In another set of cells you express a lower level of cahdherin and label those cells with a second color. Which cells are which?

Green cells have a higher level of cadherin present

Which family of cell-cell adhesion molecules has approximately 750 family members in humans and is thought to play a role in wiring of the human brain?

Ig-CAMS

You place a centrosome in a test tube that is a square plastic box the size of a cell. You add tubulin and GTP so that microtubules can be nucleated by the centrosome and be assembled in vitro. You initially place the centrosome in the lower right corner of your test tube box. Once microtubules have assembled to steady state where will your centrosome be located?

In the center of the test tube box

Immunoprecipitation can be used in conjunction with which technique to identify the protein that is recognized by a specific antibody?

Mass spec

The microtubules that attach to the chromosomes at the centromere/kinetochore attach to what?

The outer layer of the kinetochore

You perform a classic cell sorting experiment using cells from a developing Xenopus embryo. One set of cells in your experiment are derived presumptive epidermal cells the other are presumptive neural plate cells. What do you expect the arrangement of the cells to be at the end of the experiment?

The cells will form a ball where the neutral plate cells form a mass at the center which will be surrounded by a layer of epidermal cells on the surface.

In which part of dynein is the ATPase activity located? The stalk The head The stem None of the above

The head

In lecture we talked about an experiment in which a cell was cut into two pieces. One piece contained the nucleus and centrosome. The other piece was referred to as a cell fragment. That fragment contained microtubules but no centrosome. The microtubule minus were initially pointing toward the cell from which the fragment was derived and the plus ends were pointing away from the cell from which the fragment was derived. What happened the arrangement of the microtubules in the cell fragment over time?

The microtubules were eventually rearranged so that the minus ends were in the center of the fragment and the plus ends near the plasma membrane of the fragment.

In which part of dynein is the microtubule binding site located? The head The stalk The stem None of the above

The stalk

What is the most typical form of cytoplasmic dyneins that move along interphase cytoplasmic microtubules? They are trimers They are monomers They are dimers They are tetramers

They are dimers

Which type of junction prevents transmembrane proteins in the apical part of the plasma membrane from diffusing into the basolateral part of the plasma membrane?

Tight junctions

T/F As described in lecture, kinetochore microtubule begin to pull on the sister chromatids prior to anaphase.

True

T/F As described in lecture, kinetochore microtubules treadmill in M-phase prior to anaphase.

True

T/F As described in lecture, when one is studying yeast and plates for single cells, all cells within a given colony are expected to be genetically identical.

True

T/F As discussed in lecture, it takes greater than 1 full cell cycle for a centriole to mature from being "born" (or its initial formation) until it matures into a fully functional mother centriole.

True

T/F As discussed in lecture, the progenitor of the AAA ATPase family of proteins existed before the eubacteria, the archaebacteria and the eukaryotes diverged from each other.

True

T/F In the early part of mitosis, prior to anaphase chromosomes are moved to the center of the cell; whereas, in anaphase the sister chromatids move toward the spindle poles away from the center of the cell.

True

T/F MPF function is conserved from frogs to humans.

True

When dynein is in the "apo" form, what is the form of the "nucleotide" that is bound to the dynein? ADP ATP ADP + Pi no nucleotide

no nucleotide