Scaffolds for MAP kinase pathways are well documented in yeast, fly, and worm cells, but their presence in mammalian cells has been difficult to demonstrate. Perhaps the best documented scaffold protein in metazoans is Ksr (kinase suppressor of Ras).

A. Ksr functions as a molecular scaffold by binding several signaling components of the MAP kinase cascade, including both MEK and MAP kinase; and thus can enhance MAP kinase activation by regulating the efficiency of these interactions.

B. Ksr function as a protein kinase which constitutive activate RTK signalling pathway.

C. Ksr function as a receptor proteins which inhibits RTK signalling pathway.

D. Ksr function as a protein phosphatase which inhibits RTK signalling pathway.

Which of the following statement is correct about Ksr?

#Question id: 9173

#Unit 9. Diversity of Life Forms

Use the following figure to answer the question below

In the figure, which number would designate the arctic tundra biome?

#Question id: 9171

#Unit 9. Diversity of Life Forms

Suppose that the number of bird species is determined mainly by the number of vertical strata found in the environment. If so, in which of the following biomes would you find the greatest number of bird species?

#Question id: 9169

#Unit 9. Diversity of Life Forms

In areas of permafrost, stands of black spruce are frequently observed in the landscape, while other tree species are noticeably absent. Often these stands are referred to as "drunken forests" because many of the black spruce often "lean over" (that is, they are displaced from their normal vertical alignment). What is the most likely explanation for the unusual growth of these forests in this marginal habitat?

#Question id: 9164

#Unit 9. Diversity of Life Forms

Use the following figures to answer the question below.

East of the Mississippi River, in Hopkinsville Kentucky, the mean annual precipitation is 130 cm. The mean annual temperature is 14.3°C. In the winter, the mean temperature is 7.3°C, while in summer it is 20.6°C. Using the climograph shown here, how would we classify the biome found in Hopkinsville?

#Question id: 9163

#Unit 9. Diversity of Life Forms

Use the following figures to answer the question below

Based on the data in the figures, which of the following statements are correct?

I) Area 1 would be considered a desert because of its high average temperature.

II) Area 1 has more average precipitation than Area 2.

III) Area 2 would be considered a desert because of its low average precipitation.

IV) Area 2 has a larger annual temperature variation.

#Question id: 9159

#Unit 9. Diversity of Life Forms

Which of the following investigations would shed the most light on the future distribution of organisms in temperate regions that are faced with climate change?