The diagram below represents a hypothetical operon in the bacterium E. coli.  The operon consists of two structural genes (A and B) that code for the enzymes A-ase and B-ase, respectively, and also includes P (promoter) and O (operator) regions as shown.

 When a certain compound (X) is added to the growth medium of E. coli, the separate enzymes A-ase and B-ase are both synthesized at a 50-fold higher rate than in the absence of X (which has a molecular weight of about 200).  Which one of the following statements is true of such an operon?

#Question id: 5132

#Unit 5. Developmental Biology

Upon secretion of wnt, When Wnt attaches to the Frizzled receptor on a responding cell, the cell secretes Notum, a hydrolase that associates with glypican and then cleaves off Wnt’s attached lipids in a process of deacylation or delipidation. This process:

#Question id: 5133

#Unit 5. Developmental Biology

Identify the correct ligands in both receptor serine kinase pathway.

#Question id: 5134

#Unit 5. Developmental Biology

Match the following cleavage patterns with the species in which they occur.

        Species                                           Cleavage Pattern

      A. Flatworm                                       i. Meroblastic discoidal

      B. Frog                                               ii. Meroblastic superficial

      C. Birds                                              iii. Holoblastic displaced radial

      D. Insect                                              iv. Holoblastic spiral

#Question id: 5135

#Unit 5. Developmental Biology

In xenopus, result of tissue transplantation during early and late gastrulae

(A) Cells of early newt gastrula exhibit conditional development.

(B) Cells of early newt gastrula exhibit autonomous development

(C) Cells of late newt gastrula exhibit conditional development.

(D) Cells of late gastrula exhibit autonomous development.

The correct inferences are:

#Question id: 5136

#Unit 5. Developmental Biology

Some statements regarding to hippo pathway.

A. The Hippo signal transduction pathway have a dedicated ligand or receptor

B. Hippo stands for one of several important kinases that are critical for organ size control

C. It was first identified in Drosophila, where its loss resulted in a “hippopotamus”-shaped phenotype due to excessive growth

D. Gain of Hippo causes cells to divide significantly faster while slowing apoptosis

E. overexpression of its main transcriptional effector, Yorkie causes cells to divide significantly faster while slowing apoptosis

Which of the following combination are incorrect?

#Question id: 5137

#Unit 5. Developmental Biology

Match the correct animal and their mechanism of germplasm specification.