TLS Online TPP Program

#Question id: 7231


Kragl and colleagues (2009) performed an experiment in which they transplanted limb tissue from a salamander whose cells expressed green fluorescent protein (GFP) into different regions of limbs of normal salamanders that did not have the GFP transgene. If they transplanted the GFP-expressing limb cartilage into a salamander limb that did not contain the GFP transgene, the GFP-expressing cartilage would integrate normally into the limb skeleton. They later amputated the limb through the region containing GFP-marked cartilage cells. The blastema was found to contain GFP-expressing cells, and when the blastema differentiated, the only GFP-expressing cells found were in the limb cartilage. Similarly, GFP-marked muscle cells gave rise only to muscle, and GFP-marked epidermal cells only produced the epidermis of the regenerated limb. Which of the following phenomenon is proved according to experiment?

#Unit 5. Developmental Biology
  1. These results suggest that nAG alone is the primary mitogen responsible for nerve-dependent regeneration.
  2. The blastema is not a collection of unspecified multipotent progenitor cells. Rather, the cells retain their specification, and the blastema is a heterogeneous assortment of restricted progenitor cells.
  3. The blastema is a collection of unspecified multipotent progenitor cells. Rather, the cells lost their specification, and the blastema is a homogeneous assortment of restricted progenitor cells.
  4. Salamanders accomplish epimorphic regeneration by cell dedifferentiation to form a regeneration blastema, which in this case is an aggregation of relatively undifferentiated cells derived from the originally differentiated tissue that then proliferates and redifferentiates into the new limb parts.

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TLS Online TPP Program

#Question id: 4281

#Unit 3. Fundamental Processes

Proteins targeted to non-matrix regions of mitochondria

a. contain a matrix-targeting signal if the destination is the outer membrane.

b. utilize a stop-transfer signal if the destination is the outer membrane.

c. always contain a matrix-targeting signal if the destination is the intermembrane space.

d. may require a chaperone for transport.

e. always move first to the matrix and then to their final destination.

TLS Online TPP Program

#Question id: 4282

#Unit 3. Fundamental Processes

Which of the following protein(s) is (are) found in the peroxisome matrix?

TLS Online TPP Program

#Question id: 4283

#Unit 3. Fundamental Processes

Proteins can enter which organelle(s) in their folded conformation?

TLS Online TPP Program

#Question id: 4284

#Unit 3. Fundamental Processes

Assays for following the trafficking of proteins through the secretory pathway in living cells require

a. sensitive methods to distinguish the very small differences in organelle density caused by passage of a wave of protein transport through the organelle.

b. a way to identify compartments where labeled proteins are located.

c. the use of cell types that are highly dedicated secretory cells.

d. the use of enucleate cells in order to eliminate the nucleus as a site of labeling.

e. a way to label a cohort of secretory proteins

TLS Online TPP Program

#Question id: 4285

#Unit 3. Fundamental Processes

VSV G protein has been a very useful tracker protein for both living cell and in vitro assays because

TLS Online TPP Program

#Question id: 4286

#Unit 3. Fundamental Processes

Transport vesicles

a. can have a clathrin coat.     b. can be coated with a heteromeric COPI and COPII coat.

c. can contain assembly proteins.

d. can shuttle proteins from mitochondria to the endoplasmic reticulum.

e. can fuse with target organelles.