In Arabidopsis thaliana, the transition to flowering involves multiple factors, pathways and meristem identity genes. Following statements regarding to the mechanism and function of meristem identity genes.

 A. FT mRNA is expressed in companion cells of the leaf vein in response to multiple signals, including day length, light quality, and temperature.

 B. The FT–FD complex activates AP1 in the inflorescence meristem and SOC1 in the floral meristem, which triggers LFY gene expression.

 C. LFY and AP1 trigger expression of the floral homeotic genes.

 D. FLC acts as a negative regulator of SOC1 in the meristem and as a negative regulator of FT in the leaves.

 Which of the following is incorrect?

#Question id: 4957

#Unit 11. Evolution and Behavior

How many half-lives should have elapsed if 6.25% of the parent isotope remains in a fossil at the time of analysis?

#Question id: 4958

#Unit 11. Evolution and Behavior

What is true of the fossil record of mammalian origins?

#Question id: 4959

#Unit 11. Evolution and Behavior

If a fossil is encased in a stratum of sedimentary rock without any strata of igneous rock (e.g., lava, volcanic ash) nearby, then it should be

#Question id: 4960

#Unit 11. Evolution and Behavior

Letʹs say that a hypothetical submersible robot was used to collect samples of sedimentary rock from the sea floor along the section illustrated. The robot moved back and forth along the transect, collecting first from site A, then site III, then site B, then site II, and lastly site D. Assuming that sedimentation has occurred at a constant rate along the transect over the past million years, rearrange the sites mentioned above on the basis of the thickness of the sediments overlying the igneous rock, from thickest to thinnest.

#Question id: 4961

#Unit 11. Evolution and Behavior

An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to

#Question id: 4963

#Unit 11. Evolution and Behavior

Which free-living cells were the earliest contributors to the formation of Earthʹs oxidizing atmosphere?