SAT Subject Biology Practice Question 247: Answer and Explanation
17. Ecologists surveyed the composition of three different forest plots. They measured the frequency of occurrence of 13 different tree species and the basal area of each species. The basal area is calculated by measuring tree circumference at breast height and calculating the area occupied by a particular species in square meters per hectare.
Which two species are most closely related?
A. Red pine and red oak
B. Red oak and red maple
C. Red oak and American elm
D. White spruce and strobe pine
E. Quaking aspen and balsam poplar
Correct Answer: E
Quaking aspen (Populus tremuloides) and balsam poplar (Populus balsamifera) are the most closely related species. They belong to the same genus, Populus.