TLS Online TPP Program

#Question id: 5004


Pax-6 usually causes the production of a type of light-receptor pigments. In vertebrate eyes, though, a different gene (the rh gene family) is responsible for the light-receptor pigments of the retina. The rh gene, like Pax-6, is ancient. In the marine ragworm, for example, the rh gene causes production of c-opsin, which helps regulate the wormʹs biological clock. Which of these most likely accounts for vertebrate vision?

#Unit 11. Evolution and Behavior
  1. The Pax-6 gene mutated to become the rh gene among early mammals.

  2. During vertebrate evolution, the rh gene for biological clock opsin was co-opted as a gene for visual receptor pigments.

  3. In animals more ancient than ragworms, the rh gene(s) coded for visual receptor pigments; in lineages more recent than ragworms, rh has flip-flopped several times between producing biological clock opsins and visual receptor pigments.

  4. Pax-6 was lost from the mammalian genome, and replaced by the rh gene much later.

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TLS Online TPP Program

#Question id: 10471

#Unit 6. System Physiology – Plant

Under temperate conditions, which one of the two major factors that are involved with light-dependent stomatal opening are,

TLS Online TPP Program

#Question id: 10470

#Unit 6. System Physiology – Plant

when the environmental stimuli associated with high CO2 demand inside the leaf are transduced into

TLS Online TPP Program

#Question id: 10469

#Unit 6. System Physiology – Plant

When aquatic plants are kept in terrestrial habitat; what adaptations do these plants develop themselves?

TLS Online TPP Program

#Question id: 10468

#Unit 6. System Physiology – Plant

Why are stomata required in leaf surface?

TLS Online TPP Program

#Question id: 10467

#Unit 6. System Physiology – Plant

The COP1-SPA complex acts as a positive regulator as well as acts as negative regulator  by shown in statements;

a) Act as negative regulator−that targets transcription factors for degradation during phytochrome and cryptochrome responses

b) Acts as a positive regulator−that targets transcription factors for degradation during phytochrome and cryptochrome responses

c) Acts as a negative regulator− during UV-B signaling by interacting with the C-terminal region of UVR8 in the nucleus UVR8- COP1-SPA complex then activates the major transcription factor HY5, which controls the expression of many of the genes induced by UV-B

d) Acts as a positive regulator during UV-B signaling by interacting with the C-terminal region of UVR8 in the nucleus UVR8- COP1-SPA complex then activates the major transcription factor HY5, which controls the expression of many of the genes induced by UV-B

Whichof the following combination from avbove statements of UVR8 is true?

TLS Online TPP Program

#Question id: 10466

#Unit 6. System Physiology – Plant

In Arabidopsis, phot1 mutants have a normal avoidance response and a poor accumulation response, phot2 mutants lack the avoidance response but retain a fairly normal accumulation response, while phot1/phot2 double mutant lack both the avoidance and accumulation responses. These results indicate that,