As with cryptochrome and phytochrome, the N-terminal photosensory region of the phototropins controls the activity of the C-terminal half of the protein, which contains a serine/threonine kinase domain. Following are some statements about photosensory region of the phototropins.

a) The activation of the C-terminal kinase domain then leads to receptor autophosphorylation on multiple serine residues that is required for all phototropin-mediated responses

b) In the dark, the N-terminal region, including the LOV domains, “cages” and inhibits the activity of the kinase domain

c) In the light, the N-terminal region, including the LOV domains, “cages” and inhibits the activity of the kinase domain

d) Absorption of blue photons by the LOV domains results in primary photochemical changes that lead to the uncaging of the kinase domain and its activation by the unfolding of the Jα-helix

Which one of the following combination of above statements is correct?

TLS Online TPP Program

#Question id: 12965

#Unit 10. Ecological Principles

Phytoplankton is most frequently found in which of the following zones?

TLS Online TPP Program

#Question id: 12966

#Unit 10. Ecological Principles

You are planning a dive in a lake, and are eager to observe not many underwater organisms but be able to observe them both close up and far away. You would do well to choose

TLS Online TPP Program

#Question id: 12967

#Unit 10. Ecological Principles

Which of the following is the best explanation for why net primary productivity in terrestrial ecosystems tends to increase toward the tropics?

TLS Online TPP Program

#Question id: 12968

#Unit 10. Ecological Principles

Most terrestrial ecosystems have a pyramidal structure of where biomass of producers > primary consumers > secondary consumers > tertiary consumers. However, some aquatic ecosystems have an inverted pyramidal structure where the standing biomass of producers < primary consumers. An explanation for this is:

TLS Online TPP Program

#Question id: 12969

#Unit 10. Ecological Principles

In which of the following habitats would one expect to find the highest diversity of vascular plants? 

TLS Online TPP Program

#Question id: 12970

#Unit 10. Ecological Principles

In deep-sea hydrothermal vents near the Galapagos Islands, bacteria obtain energy by oxidizing hydrogen sulphide released from the vents. Giant tube worms, which lack mouths and digestive systems, harbour the bacteria in their tissues and use them as a source of organic molecules. Clams obtain energy by filtering bacteria directly from the water, and numerous crabs and octopi feed on the clams. In this unique ecosystem, the bactena are playing the role of