In sea urchin, the large micromeres are autonomously specified. They inherit maternal determinants that were deposited at the vegetal hemisphere of the egg; these become incorporated into the large micromeres at fourth cleavage. When an isolated animal hemisphere is combined with isolated micromeres, then what will be the result?

#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.

#Question id: 5138

#Unit 5. Developmental Biology

When presomitic mesoderm (PSM) that would ordinarily form thoracic somites is transplanted into a region in a younger embryo (caudal to the first somite) that would ordinarily give rise to cervical (neck) somites, the grafted mesoderm differentiates according to its original position and forms ribs in the neck. This phenomena is called as:

#Question id: 5139

#Unit 5. Developmental Biology

There are two broad categories of receptors that activate tyrosine kinases: (1) those in which the tyrosine kinase enzyme is an intrinsic part of the receptor’s polypeptide chain, called the_________ and (2) those, in which the receptor and kinase are separate polypeptides, encoded by different genes, yet are bound tightly together, called the __________.

#Question id: 5140

#Unit 5. Developmental Biology

Following statements regarding to the Ectodermal competence and the ability to respond to the optic vesicle inducer in Xenopus.

A. The optic vesicle is able to induce lens formation in the posterior portion of the ectoderm but not in the anterior portion.

B. If the optic vesicle is removed, the surface ectoderm forms either an abnormal lens or no lens at all.

C. Only head ectoderm is competent to respond to the signals from the optic vesicle by producing a lens.

D. The head ectoderm appears to secrete two paracrine factors BMP 4 and FGF8, which involves in the activation of lens-specific genes such as crystallin.

Which of the following combination is incorrect?

#Question id: 5141

#Unit 5. Developmental Biology

Which of the following statement not describe the concept of morphogenetic gradient?