Following statements are regarding to the wnt signalling.

A. Wnt proteins interact with several cell-surface proteins and activate multiple downstream signal transduction pathways. The principal signaling receptor for Wnt proteins is Frizzled (Fz), which contains seven transmembrane α helices.

B. The palmitate attached to the Wnt protein binds to a specific site on the Fz intracellular domain and stabilizes the Wnt-Fz complex.

C. “canonical” Wnt signaling pathway uses a second transmembrane protein, LRP, that associates with Frizzled in a Wnt signal– dependent manner.

D. In the resting state, two kinases in the complex, casein kinase 1 (CK1) and GSK3, sequentially phosphorylate β-catenin on multiple tyrosine residues.

Which of the following statements are correct?

#Question id: 26555

#Unit 3. Fundamental Processes

Which of the following is incorrect about Dicer

#Question id: 5289

#Unit 8. Inheritance Biology

A donor strain of bacteria with genes a+b+c+ is infected with phages to map the donor chromosome with transduction. The phage lysate from the bacterial cells is collected and used to infect a second strain of bacteria that are a_ b_ c_.

Based on the above, which one of the following conclusions is correct?

#Question id: 28213

#Unit 5. Developmental Biology

Specification of different mesodermal cell types in the frog Xenopus laevis by activin, a paracrine factor of the TGF-beta family. Which of the following observation is correct at the high concentration of activin?

#Question id: 1529

#Unit 4. Cell Communication and Cell Signaling

Which of the following statements are true regarding to gain-of-function and loss-of-function mutations with respect to cancer.

#Question id: 2152

#Unit 2. Cellular Organization

Precursors of membrane phospholipids are

a. soluble in the cytosol.                    

b. incorporated into biosynthetic intermediates.

c. sometimes complexed with fatty-acid-binding proteins.

d. stored in glycerolosomes.

e. sometimes activated by conjugation with CDP.