The regeneration blastema forms from pluripotent stem cells called clonogenic neoblast. If cNeoblasts are essential for regeneration, their total loss should prevent regeneration. Following statements are made in respect to planaria regeneration are given below.

(A) The gene sigma/zeta is expressed by all neoblasts and has become the most common marker for their identification across planarian species.

(B)   In planaria, Wnt/β-catenin functions to establish dorsal ventral polarity of the regenerating flatworm.

(C)   Inhibition of Wnt/β-catenin signaling in regeneration-deficient species yields fully functional regenerated heads.

(D)   If β-catenin is eliminated from the posterior (tail-forming) blastema by RNA interference, that blastema will form a tail.

Which of the above statements are true?

#Question id: 7179

#Unit 5. Developmental Biology

Blocking BMP(BMP2, BMP4, BMP7) signaling by infecting progress zone cells with retroviruses carrying dominant negative BMP receptors. Which of the following results are found?

#Question id: 7180

#Unit 5. Developmental Biology

Development of tetrapod limb has to function in a three dimensional coordinated system:

Proximal-distal axis by ____a_____

Anterior-posterior axis by ___b_____

Dorsal-ventral axis by ______c____

Which of the following combinations are correct?

#Question id: 7181

#Unit 5. Developmental Biology

Following graph represents Inhibition of L1-mediated cell adhesion by alcohol.

If L1 is mutate, which of the following graph is correct?

#Question id: 7182

#Unit 5. Developmental Biology

Suppose a flower had normal expression of genes A and C and expression of gene B in all four whorls. Based on the ABC hypothesis, what would be the structure of that flower, starting at the outermost whorl?

#Question id: 7183

#Unit 5. Developmental Biology

Following graphs (A and B) represents establishment of a maternal gradient in Hunchback protein.

which of the following statements are correct according to graphs?

#Question id: 7184

#Unit 5. Developmental Biology

The figure above represents a late zebrafish gastrula. The following concepts may be proposed during further development of the embryo.

A. The concentration of FGF decreases from the yolk towards the epidermis, along with the increase of BMP activity from the dorsal to the ventral axis.

B. Increase in FGF activity in the epidermis with concomitant decrease in BMP activity towards the ventral axis.

C. Neural induction in zebrafish is independent of the organizer and depends on activation of BMP signalling.

D. In comparison, both Xenopus and chick embryos require activation of FGF for neural induction to occur in addition to BMP inhibition.

Which of the above statements are incorrect?