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: 18742

#Unit 13. Methods in Biology

When inserting a DNA fragment, it is possible to have two orientations. If the orientation is controlled, this cloning is referred to as __________

TLS Online TPP Program

#Question id: 18743

#Unit 13. Methods in Biology

What happens if insert DNA is cut with two different restriction enzymes at the ends?

TLS Online TPP Program

#Question id: 18744

#Unit 13. Methods in Biology

What is the disadvantage of amplification of using PCR over natural cloning?

TLS Online TPP Program

#Question id: 18745

#Unit 13. Methods in Biology

If linkers are combined with the features such as antibiotic resistance, They may also contain gene expressing signals, these are called as…………. 

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#Question id: 18746

#Unit 13. Methods in Biology

Which of the following is a characteristic of Taq polymerase?

TLS Online TPP Program

#Question id: 18747

#Unit 13. Methods in Biology

These are steps taken in carrying out the PCR reaction:

i) Attaching of primers by cooling

ii) Denaturation of strands

iii) DNA synthesis

iv) Heating

Which is the correct order?

(Mentioned from starting to ending the reaction)