____________ is the physical place where a species lives.

#Question id: 7208

#Unit 5. Developmental Biology

Following statements are given about cleavage in drosophila.

A. During the ninth division cycle, approximately five nuclei reach the surface of the anterior pole of the embryo. These nuclei become enclosed by cell membranes and generate the pole cells that give rise to the gametes of the adult.

B. During tenth division of cycle, the other nuclei migrate to the cortex (periphery) of the egg and at this stage, embryo is called a syncytial blastoderm .

C. When the nuclei reach the periphery of the egg during the tenth cleavage cycle, each nucleus becomes surrounded by microtubules and microfilaments. The nuclei and their associated cytoplasmic islands are called  transmembrane.

D. Following division cycle 13, the cell membrane (which had covered the egg) folds inward between the nuclei, eventually  partitioning off each energid into a single cell. This process creates the cellular blastoderm.

Which of the following combination are correct?

#Question id: 7209

#Unit 5. Developmental Biology

Following statements are related to the Epigenetic regulation of Hox gene expression in the chick limb .

A. Hoxa13 is normally not expressed during early limb bud outgrowth.

B. Hoxa13 is normally expressed during early limb bud outgrowth.

C. Inhibition of histone deacetylases with a TSA-coated bead implanted into the early limb bud results in precocious Hoxa13 expression and specifically reduced skeletal elements of the zeugopod

D. Inhibition of HAT proteins with a TSA-coated bead implanted into the early limb bud results in Hoxa13 expression and specifically reduced skeletal elements of the zeugopod

E. The epigenetic hold on gene Hoxa13 expression to allow the necessary time for zeugopod development.

F. The epigenetic hold on gene Hoxa13 expression to allow the necessary time for autopod development.

Which of the following combinations are correct?

#Question id: 7210

#Unit 5. Developmental Biology

Model for limb patterning by opposing gradients of retinoic acid (blue shading) and of FGFs and Wnts (pink shading). According to this graph, Which of the following statements are correct?

#Question id: 7211

#Unit 5. Developmental Biology

Choose the correct match.

#Question id: 7212

#Unit 5. Developmental Biology

The regeneration blastema forms from pluripotent stem cells called clonogenic neoblast. If cNeoblasts are essential for regeneration, their total loss should prevent regeneration. Following statements are made in respect to planaria regeneration are given below.

(A) The gene sigma/zeta is expressed by all neoblasts and has become the most common marker for their identification across planarian species.

(B)   In planaria, Wnt/β-catenin functions to establish dorsal ventral polarity of the regenerating flatworm.

(C)   Inhibition of Wnt/β-catenin signaling in regeneration-deficient species yields fully functional regenerated heads.

(D)   If β-catenin is eliminated from the posterior (tail-forming) blastema by RNA interference, that blastema will form a tail.

Which of the above statements are true?

#Question id: 7213

#Unit 5. Developmental Biology

Following statements are regarding to the early development of C.elegans (expression of PIE-1):

A. Segregation of PIE-1 determinant into the P1 blastomere at the 2-cell stage

B. The sperm centrosome activates the presence of the PAR-3/PAR-6 complex in the posterior of the egg

C. PIE-1 is degraded in the resulting anterior AB cell, it is preserved in the posterior P1 cell

D. PIE-1 is degraded in the resulting posterior P1 cell, it is preserved in the anterior AB cell

Which of the following combination is incorrect?