The larvae of some insects are merely small versions of the adult, whereas the larvae of other insects look completely different from adults, eat different foods, and may live in different habitats. Which of the following most directly favors the evolution of the latter, more radical, kind of metamorphosis?

#Question id: 31371

#Unit 2. Cellular Organization

#Question id: 3286

#Unit 11. Evolution and Behavior

 In a human population, the gene frequencies of the alleles for the ABO system are as follows:

A = 29%                         B = 7%                                    0=64%

Assuming complete random mating and Hardy-Weinberg equilibrium,

What are the blood type A frequencies in this population?

#Question id: 1257

#Unit 4. Cell Communication and Cell Signaling

Following statements are regarding to protein kinase A which phosphorylates multiple intracellular target proteins expressed in different cell types.

A. Inactive PKA is a tetramer consisting of two regulatory (R) subunits and two catalytic (C) subunits.

B. Each R subunit contains a pseudo-substrate domain whose sequence resembles that of a peptide substrate and binds to the active site in the catalytic domain but is not phosphorylated; thus the pseudo-substrate domain inhibits the activity of the catalytic subunits.

C. active PKA is turned off by binding of cAMP Each R subunit has two distinct cAMP-binding sites, called CNB-A and CNB-B.

D. Binding of cAMP by an R subunit of PKA occurs in a cooperative fashion; that is, binding of the first cAMP molecule to CNB-B increases the Kd for binding of the second cAMP to CNB-A. Thus small changes in the level of cytosolic cAMP can cause proportionately large changes in the number of dissociated C subunits and, hence, in cellular kinase activity.

Which of the following statements are incorrect?

#Question id: 23705

#Unit 13. Methods in Biology

#Question id: 10542

#Unit 6. System Physiology – Plant

Following are certain strategies used by pathogen to attack over the host plant that describe plant-pathogen interactions:

                      I                                                                                             II

A. Necrotrophic pathogens                              i) most of the plant tissue remains alive and only minimal cell damage can be observed, as the pathogens feed on substrates provided by their host

B. Biotrophic pathogens                                 ii) In which the host cells are kept alive as described for biotrophic  Pathogens and followed by a necrotrophic stage, in which the pathogens can cause extensive tissue damage

C. Hemibiotrophic pathogens                         iii) attack their host by secreting cell wall–degrading enzymes or toxins, which eventually kill the affected plant cells, leading to extensive tissue maceration. This dead tissue is then colonized by the pathogens and serves as a food source

Which of the following above combination is correct?