Which layer of the earth is believed to have the most nickel? a) core b) mantle c) oceanic crust d) continental crust

Which of the following statements about c4 carbon fixation is not true? a c4 carbon fixation is an adaptation for plants exposed to high light intensityb. c4 carbon fixation occurs in more plants than c3 carbon fixation. c c4 carbon fixation is more common in areas of high temperatures than c3 carbon fixation. d. c4 carbon fixation occurs in the inner cells of a leaf rather than the entire leaf.

Which of these is a major trend in land plant evolution? a) the trend toward smaller size b) the trend toward a gametophyte-dominated life cycle c) the trend toward a sporophyte-dominated life cycle d) the trend toward larger gametophytes

In which situations is the principle of cross-cutting relationship useful in determining relative age?