In the case of the French flag model. we assume a source of morphogen at one end and a sink at the other and that the concentrations of morphogen at both ends are kept constant but are different from each other. If the cells can respond to threshold concentrations of the morphogen, Thresholds can represent the

a. amount of morphogen that must bind to receptors to activate an intracellular signaling system. 

b. concentrations of transcription factors required to activate particular genes.

c. concentration at any point effectively provides positional information.

d. amount of morphogen that must bind to receptors to inactivate an extracellular signaling system.

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#Question id: 15298

#Unit 5. Developmental Biology

In mammalian development Prior to blastocyst formation, each embryonic blastomere expresses ________ transcription factors and appears to be capable of becoming either ICM or trophoblast.

TLS Online TPP Program

#Question id: 15299

#Unit 5. Developmental Biology

Name of transcription factor which are responsible for  pluripotency of  stem cells or stimulate the production of OCT4 and NANOG ;

TLS Online TPP Program

#Question id: 15300

#Unit 5. Developmental Biology

In hippo signaling pathway, the activation of the Cdx2 gene in the trophoblast cells appears to be regulated by the Yap protein, which in turn is a cofactor for the transcription factor Tead4. Tead4 is found in the ________blastocyst

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#Question id: 15301

#Unit 5. Developmental Biology

Initially, the morula does not have an internal cavity. However, during a process, cavitation, the trophoblast cells secrete fluid into the morula to create a blastocoel, these 

membranes of trophoblast cells contain_______?

TLS Online TPP Program

#Question id: 15302

#Unit 5. Developmental Biology

FOXP1 is a transcription factor which stimulate the production of Oct4 and Nanog and establish pluripotency. Which of the following statements are correct regarding to the mechanism of alternative splicing of FOXP1. 

A. There are two isoforms of the FoxP1 protein, One is the product of an mRNA spliced to include a particular exon, 18b, while the other splicing variant carries exon 18a.

B. When alternative splicing generates a form including exon 18b in place of 18a, the resulting isoform (FOXP1-ES) binds to a different DNA sequence and thus controls expression of a different set of genes.

C. The protein encoded by the exon 18b– carrying mRNA is called FOXP1-ES it fails to stimulate expression of OCT4 and NANOG and instead actives genes that promote differentiation. 

D. The exon 18a– containing form encodes FOXP1 itself, and this has the opposite effect: this activates genes that promote dedifferentiation, and thus stimulates iPS cell formation.

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#Question id: 15391

#Unit 5. Developmental Biology

In the initiation of the vertebrate eyes, paired regions of the brain bulge out and approach the anterior region of -------germ layer: