Choose correct statements about synthesis and processing of antidiuretic hormone and oxytocin.

a. ADH and oxytocin are homologous nonapeptides (containing nine amino acids).

b. Are synthesized in the supraoptic and paraventricular nuclei of the hypothalamus respectively.

c. The ADH neurons have their cell bodies primarily in the paraventricular nuclei.

d. The oxytocin neurons have their cell bodies primarily in supraoptic nuclei of the hypothalamus.

#Question id: 7223

#Unit 5. Developmental Biology

In drosophila, the dorso-ventral axis of the embryo becomes divided into four regions early in embryogenesis.

A. The ventral mesoderm, which will form muscles and other internal connective tissues

B. The amnioserosa, which gives rise to an extra-embryonic membrane on the dorsal side of the embryo

C. The dorsal ectoderm, which gives rise to larval epidermis

D. The ventral ectoderm or neuroectoderm, which gives rise to the larval nervous system and epidermis

What is the correct sequence of these regions from ventral to dorsal?

#Question id: 7224

#Unit 5. Developmental Biology

Following statements are given regarding to the migration through primitive streak in chick.

A. Cells migrate to the primitive streak, and as they enter the embryo, the deep-moving cells give rise to the endodermal organs of the embryo, as well as to most of the extraembryonic membranes.

B. The migration of mesodermal cells through the anterior primitive streak and their condensation to form the chordamesoderm also appear to be controlled by FGF and Wnt signalling.

C. Wnt is expressed in the primitive streak and repels migrating cells away from the streak. 

D. Once cells migrate away from the streak, further movement of the mesodermal precursors appears to be regulated by FGF8 proteins.

Which of the following statement is incorrect?

#Question id: 7225

#Unit 5. Developmental Biology

The processes by which the three ectodermal regions are made physically and functionally distinct from one another is called neurulation. Following statements are regarding to the mechanism of neurulation.

A. The specification of the ectoderm is accomplished during gastrulation, primarily by regulating the levels of BMP experienced by the ectodermal cells.

B. High levels of BMP specify the cells to become neural plate.

C. Very low levels specify the cells to become epidermis.

D. Intermediate levels effect the formation of the neural crest cells.

Which of the following combination is correct?

#Question id: 7226

#Unit 5. Developmental Biology

Experimental evidences suggest that control of proximal-distal specification of the limb is correlated with the age of the progress zone mesenchyme. Match the following experiment (Column I) with their results (Column II).

#Question id: 7227

#Unit 5. Developmental Biology

The regulative ability of the limb bud has recently been highlighted by a remarkable experiment of nature. In numerous ponds in the United States, multilegged frogs and salamanders have been found. The presence of these extra appendages has been linked to the infestation of the larval abdomen by parasitic trematode worms. The eggs of these worms apparently split the developing tadpole limb buds in several places, and the limb bud fragments develop as multiple limbs. This shows:

A. The limb field represents a harmonious equipotent system. 

B. The limb field do not represents harmonious equipotential system because different types of genes express during proximal to distal growth.

C. The limb field represents coupled system wherein one gene maintain the expression of other genes.

D. The limb field represents a harmonious equipotent system because only Hox genes expresses all along the limb axis.

E. The limb field represents cells of the limb region can be instructed to form any part of the limb. 

Which of the following statements are correct?

#Question id: 7228

#Unit 5. Developmental Biology

Why do Drosophila wings develop in only one particular thoracic segment, legs in all three, and antennae on the head? Which of the following answer is correct?