Which of the following statements is true about formation of the primitive streak ?

A. by the cellular dance mechanism, the cells came down the sides of the epiblast to undergo a medially directed intercalation of cells in the posterior margin where primitive streak forms.

B. Cellular dance is mediated by wnt planar cell polarity pathway in the hypoblast cells, at the posterior edge of the embryo.

C. The Wnt pathway activated by fibroblast growth factors (FGFs) produced by the hypoblast.

D. The Wnt planar cell polarity pathway activated by b-catenin produced by the epiblast.

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#Question id: 11652

#Unit 10. Ecological Principles

The sequence of changes initiated by disturbance is called succession, and the ultimate association of species achieved is called

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#Question id: 7514

#General Aptitude

A train running at 8/11 of its own speed reached a place in 11/2 h. How much time could be saved, if the train would have run at its own speed?

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#Question id: 27495

#Unit 1. Molecules and their Interaction Relevant to Biology

A mixture containing two enantiomers in equal proportions will have

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#Question id: 12854

#General Aptitude

If the ratio of areas of two squares is 225 : 256, then the ratio of their perimeter is :

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#Question id: 1844

#Unit 4. Cell Communication and Cell Signaling

Which of the following diseases has been completely eradicated worldwide?