Following statements are regarding to anterior-posterior polarity in planaria.

A. The anterior expression of Notum functions to antagonize the posteriorly produced Wnt, leading to head specification.

B. Regulation of the balance between Wnt and Notum signals may underlie not only head-tail specification but also regulation of organ size.

C. In addition, there appears to be an anterior-to-posterior gradient of Erk signaling that functions as a positive inducer of tail specification.

D. Wnt signaling achieves its repression of head regeneration by inhibiting Erk. Therefore, only in those more anterior regions lacking Wnt (due to Notum’s repression of Wnt) can Erk induce head regeneration.

Which of the following statements are incorrect?

TLS Online TPP Program

#Question id: 15331

#Unit 4. Cell Communication and Cell Signaling

B-cell surface contain marker_______

TLS Online TPP Program

#Question id: 15776

#Unit 5. Developmental Biology

Which stem cells play critical roles in fueling organogenesis in the embryo and regeneration in adult tissues?

A. Adult stem cells.

B. Embryonic stem cells

C. True stem cells

D. Tissue specific stem cells

TLS Online TPP Program

#Question id: 29576

#Unit 6. System Physiology – Plant

…a…..is a TAL effector of the rice pathogen Xanthomonas oryzae, activates expression of the rice gene ….b….. allowing Xanthomonas to colonize rice plants 

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#Question id: 26981

#Unit 10. Ecological Principles

Life history features of r-selected species is

TLS Online TPP Program

#Question id: 27480

#Unit 1. Molecules and their Interaction Relevant to Biology

Enantiomers are