Assertion (A): Prolactin stimulates the synthesis of casein and lactalbumin during lactation without acting directly on the cell nucleus.

Reason (R): The action of prolactin is dependent on intact microtubules, suggesting involvement of cytoplasmic transport or signaling components.

Choose the correct option:

#Question id: 7258

#Unit 5. Developmental Biology

A four-cell embryo normally develops into a blastocyst consisting of trophectoderm (TE) cells on the outside and inner cell mass (ICM) cells inside. The transplantation experiments were done with mouse embryos.

A. If a labeled cell is placed on the outside of a very early embryo, it is likely to form extraembryonic tissues.

B. If a labeled cell is placed on the inside of a very early embryo, it is likely to form embryonic tissues.

According to above observations which of the following statement is true?

#Question id: 7259

#Unit 5. Developmental Biology

The mechanism that triggered to initiate limb bud formation involes:

A. making mesoderm instructive for limb formation

B. inducing epithelial-to-mesenchymal transitions

C. making mesoderm permissive for limb formation

D. inducing mesenchymal-to-epithelial transitions

E. specifying forelimb and hindlimb

Which of the following combinations are incorrect?

#Question id: 7260

#Unit 5. Developmental Biology

There are maternally-determined variations along the animal-vegetal axis that are necessary for normal development in sea urchin. Which of the following statements about regulation in sea urchin embryos is consistent with that fact?

#Question id: 7261

#Unit 5. Developmental Biology

The Turing model provides a framework for limb development. Following statements are regarding to this model:

A. In Turing’s model, morphogen A promotes the production of more morphogen A (autoactivation) as well as production of morphogen I. Morphogen I, however, inhibits the production of morphogen A (lateral inhibition).

B. In Turing’s model, morphogen A inhibits the production of more morphogen A (autoinhibition) as well as production of morphogen I. Morphogen I, however, promotes the production of morphogen A (lateral activation).

C. In Turing’s model, the reaction-diffusion dynamics can tell us how the limb bud acquires its proximal- distal polarity as well as how the number of digits is regulated at the distal tip of the limb.

D. The reaction-diffusion system has been proposed to be sufficient for establishing patterns of precartilage and noncartilage tissues.

E. According to this model, along the proximal-distal axis the AER dividing into two domains 1-the inhibitory domain 2-the active domain.

F. According to this model, along the proximal-distal axis the AER dividing into three domains 1-the inhibitory domain 2-the active domain 3-frozen domain.

Which of the following combinations are incorrect?

#Question id: 7262

#Unit 5. Developmental Biology

Match the following Gene (column I) with their function (column II).

Which of the following is correct?

#Question id: 7263

#Unit 5. Developmental Biology

Following statements are regarding to the drosophila.

 A. At the completion of oogenesis, the bicoid message is anchored at the anterior end of the oocyte and the nanos message is tethered to the posterior end in translationally dormant condition.

 B. The translation inhibitors Smaug and CUP. Smaug binds to the 3’UTR of both bicoid and nanos mRNA and recruits the CUP protein that prevents the association of the message with the ribosome as well as recruiting other proteins that deadenylate the message and target it for degradation.

 C. The bicoid-Exuperantia complex is transported out of the nurse cells and into the oocyte via microtubules (Kinesin ATPase).

 D. Two other maternally provided mRNAs—caudal and hunchback are critical for patterning the anterior and posterior regions of the body plan, respectively.

 Which of the following combination is correct?