TLS Online TPP Program

#Question id: 5003


Fruit fly eyes are of the compound type, structurally very different from the camera-type eyes of mammals. Even the camera-type eyes of mollusks, such as octopi, are structurally quite different from those of mammals. Yet, fruit flies, octopi, and mammals possess very similar versions of Pax-6. The fact that the same gene helps produce very different types of eyes is most likely due to

#Unit 11. Evolution and Behavior
  1. the few differences in nucleotide sequence among the Pax-6 genes of these organisms.

  2. variations in the number of Pax-6 genes among these organisms.

  3. the independent evolution of this gene at many different times during animal evolution.

  4. differences in the control of Pax-6 expression among these organisms.

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TLS Online TPP Program

#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?

TLS Online TPP Program

#Question id: 7262

#Unit 5. Developmental Biology

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

   

 Column I

 Column II

A. sex-lethal

i. facilitates transcription from the X chromosome

B. double-sex

ii. help  to generate the female phenotype by splicing the doublesex gene

C. msl

iii. encodes an RNA splicing factor

D. transformer

iv. activate wingless gene in female

 

Which of the following is correct?


TLS Online TPP Program

#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?

TLS Online TPP Program

#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?


TLS Online TPP Program

#Question id: 5522

#Unit 5. Developmental Biology

In reptiles, birds, and mammals, mesoderm is made by invagination and involution into the

TLS Online TPP Program

#Question id: 5523

#Unit 5. Developmental Biology

Ectodermal cells condense into placodes that change into