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#Question id: 7220


The anterior-posterior polarity of the drosophila embryo is established while the oocyte is still in the egg chamber, and it involves interactions between the developing egg cell and the follicular cells that enclose it. Following are certain statements:

A. The gurken message appears to be synthesized in the oocyte, and it is transported into the nurse cells. Here it becomes localized between the nucleus of nurse cells and the cell membrane, and it is translated into Gurken protein.

B. Gurken signal is received by the follicle cells at that position through a receptor protein encoded by the torpedo gene.

C. This signal results in the “posterior -anteriorization” of these follicle cells.

D. Posterior follicle cells signals to recruit Par-1 protein organizes microtubules specifically with their minus (cap) and plus (growing) ends at the anterior and posterior ends of the oocyte, respectively.

E. The motor protein kinesin, is an ATPase that will use the energy of ATP to transport material to the plus end of the microtubule. Dynein, however, is a “minus-directed” motor protein that transports its cargo in opposite direction.

F. These zygotic messengers bicoid and nanos mRNAs are carried by motor proteins along the microtubules to the anterior and posterior ends of the oocyte, respectively.

Which combination of the above statements are correct?

#Unit 5. Developmental Biology
  1. A, B and C
  2. B, D and E
  3. C, E and F
  4. A, D and C
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TLS Online TPP Program

#Question id: 3261

#Unit 11. Evolution and Behavior

A parent population (P) is change into daughter populations (Q) which grow in habitats. After 1000 generations, the equilibrium frequency distribution of of the daughter populations is shown in the figure below. For reference, the vertical line represents the mean of the parent population. Which type of natural selection?

TLS Online TPP Program

#Question id: 3262

#Unit 11. Evolution and Behavior

In a population, the genotype frequencies are: f(A1A1)= 0.35; f(A1A2) = 0.30; f(A2A2) = 0.35; Which of the following statement is correct?

TLS Online TPP Program

#Question id: 3263

#Unit 11. Evolution and Behavior

From an evolutionary point of view, plant tendrils derived from leaves and those derived from stems are examples of

TLS Online TPP Program

#Question id: 3264

#Unit 11. Evolution and Behavior

Which of the following is (are) true of natural selection?

TLS Online TPP Program

#Question id: 3265

#Unit 11. Evolution and Behavior

If the curve shifts to the left or to the right, there is no gene flow, and the population size consequently increases over successive generations, then which of these is (are) probably occurring?

TLS Online TPP Program

#Question id: 3266

#Unit 11. Evolution and Behavior

One species mates at the season when daylight is increasing from 13 hours to 13 hours, 15 minutes; another species mates at the season when daylight is increasing from 14 hours to 14 hours, 15 minutes. The isolating mechanism is