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?

#Question id: 29075

#Unit 10. Ecological Principles

Identify the pollinators for the flowers with following pollination syndromes

I- Flowers evolved features such as blue purple yellow and various other except red

II- Flowers evolved features such as no fragrance because their pollinators has poor sense of smell

III- Flowers only white or light , reflective colors only with strong odori because their pollinators has good sense of smell

IV- flower has every colour including red colour with light floral scent and also providing landing place for nectar

#Question id: 29076

#Unit 10. Ecological Principles

Corals and the Dinoflagellates showing which type of mutualism

#Question id: 29077

#Unit 10. Ecological Principles

The relationship between acacia plants and the ants that live within their thorns is

#Question id: 29078

#Unit 10. Ecological Principles

A specific kind of parasitism proposes that  in which cuckoos or cowbirds repeatedly check their host’s nests and destroy all eggs if their owner is not present. If the parasite egg has been removed, they destroy the host’s nest and kill or injure the nestlings, this is an example of____

#Question id: 29079

#Unit 10. Ecological Principles

You observed the two species of barnacles, P. aurelia and P. caudatum, occupy upper and lower strata of intertidal rocks, respectively. Only when P. caudatum was removed by you from the lowers strata, P. aurelia could occupy both the upper and lower strata. From the choice given below what would be your inference from these observations.

#Question id: 29080

#Unit 10. Ecological Principles

Invasive species are less impacted by enemies than native species. An explanation for the better growth and propagation of invasive species in comparison to their native counterparts is provided by which one of the following hypotheses?