Refer to the following experiment, which is designed to test the co evolutionary relationships among an unpalatable butterfly (the  monarch),  a  palatable  butterfly  (the  viceroy),  and  a  butterfly  predator  (the  jay).  Monarch butterflies are reared on three diets: milkweed (their natural food), cabbage, and cabbage treated with an extract from milkweed leaves. Viceroy butterflies, mimics of monarchs, also are reared on three diets: willows (their natural food), cabbage, and cabbage treated with an extract from milkweed leaves. In trial 1 of the first experiment, adult butterflies reared on a particular diet are presented one at a  time  at  1-hour  intervals  to  jays  and  the  jays  are  allowed  to  feed.  Each jay is  fed  until  it refuses to eat the butterfly presented, but no more than 12 butterflies are presented to a jay during a particular test. Five birds are used for each test; therefore, up to 60 butterflies can be consumed for each diet test. The observer records the actual number of butterflies  eaten. In trial 2, the experiment is repeated 2 weeks later. In the second experiment, the butterflies are reared on the same diets as in experiment 1. However, when they are offered to jays, some jays receive a monarch  reared  on  milkweed  before  being  offered  the  butterflies  reared  on  the  experimental  diets;  the  other  group  of jays is  first given a viceroy reared on willow before being  offered the butterflies reared on the experimental diets. The initial butterfly offered is included in the total number eaten, but no more than 12 butterflies are presented to each jay

Which of the following supports the hypothesis that viceroys receive protection from predation because they resemble monarchs?

#Question id: 5141

#Unit 5. Developmental Biology

Which of the following statement not describe the concept of morphogenetic gradient?

#Question id: 5142

#Unit 5. Developmental Biology

The D set of blastomeres is the “organizer” of snail embryos. Experiments have demonstrated that the non-diffusible polar lobe [cortical] cytoplasm that is localized to the D blastomere is extremely important in normal molluscan development.  Which of the following is incorrect?

#Question id: 5143

#Unit 5. Developmental Biology

Select the correct sequence of events in photoreceptor induction in drosophila.

A. Morphogenetic furrows moves across eye disc

B. Eyeless gene expression

C. R8 photoreceptor cells develop

D. R7 photoreceptor cells develop

#Question id: 5144

#Unit 5. Developmental Biology

Following statements regarding to noncanonical wnt pathways.

A. The planar cell polarity, or PCP, pathway functions to regulate the actin and microtubule cytoskeleton, thus influencing cell shape, and often results in bipolar protrusive behaviors necessary for a cell to migrate.

B. Wnts (such as Wnt5a and Wnt11) can activate Disheveled by binding to a different receptor (Frizzled paired with Ror instead of Lrp5), and this Ror receptor complex phosphorylates Disheveled in a way that allows it to interact with Rho GTPases.

C. Wnt/PCP signaling through cytoskeleton control can direct cells to divide in the different plane ( forming upper and lower tissue compartments) and to move within that different plane.

D. the Wnt/calcium pathway leads to the release of calcium stored within cells, and this released calcium acts as an important secondary messenger to activates a phospholipase (PLC) whose enzyme activities release a compound that in turn releases calcium ions from the cytosol.

Which of the following is incorrect?

#Question id: 5145

#Unit 5. Developmental Biology

Doris Taylor’s research group used detergents to remove all the cells from a cadaveric rat heart, which left behind the natural extracellular matrix. Proteins such as fibronectin, collagen, and laminin held together the rest of the extracellular matrix and maintained the intricate shape of the heart. The researchers then infused this extracellular matrix scaffold with cardiomyocyte progenitor cells. Surprisingly, these cells differentiated and organized into a functionally contracting “recellularized” heart. The behavior of extracellular matrix scaffold can promote the differentiation and rebuilding of a beating heart is analogous to which of the interactions?

#Question id: 5146

#Unit 5. Developmental Biology

Choose the correct match.