In the amoeba Dictyostelium discoideum, cAMP acts as an extracellular signalling molecule and binds to and signals via a G protein–coupled receptor; it is not a second messenger. Amoeba cells were transfected with genes encoding two fusion proteins: a Gα fused to cyan fluorescent protein (CFP), and a Gβ fused to yellow fluorescent protein (YFP). CFP normally fluoresces 490-nm light; YFP, 527-nm light. In which conditions fluorescence

energy transfer occur from CFP to YFP?

#Question id: 9201

#Unit 9. Diversity of Life Forms

Erwin and Scott used an insecticidal fog to knock down insects from the top section of a L. seemannii tree. The researchers identified over 900 species of beetles among the individuals that fell. Erwin also projected that this entire tree from top to bottom is host to about 600 arthropod species that are unique to this tree species and not found on any other tree species. There are approximately 50,000 species of tropical trees. Although it could not be entirely accurate, what would be the best way to estimate the total number of arthropod species?

#Question id: 9202

#Unit 9. Diversity of Life Forms

Which of the following statements regarding extinction is accurate?

#Question id: 9203

#Unit 9. Diversity of Life Forms

The human impact that scientists determined has caused the most extinctions on record is ________, and beyond further losses from this impact, the other impact with the largest potential to cause future extinctions is ________.

#Question id: 9204

#Unit 9. Diversity of Life Forms

Which of the following observations provides the best evidence of a biodiversity crisis?

#Question id: 9205

#Unit 9. Diversity of Life Forms

Which of the following terms includes all of the others?

#Question id: 9206

#Unit 9. Diversity of Life Forms

To better comprehend the magnitude of current extinctions, it will be necessary to ________.