Which of the following best explains why there are seldom more than five trophic levels in a food chain?

All the following provide evidence and support for the theory of natural selection except ______.

Which of these organisms are most closely related? At the left is a branch point from which two lines extend. The upper line extends upward to the right, reaching a second branch point. From this second branch point, the upper line extends upward to the right, leading to Tuatara. The lower line from the second branch point extends to the right, then branches twice more, creating two upper lines that extend upward to the right and one lower line. A bracket to the right indicates that the two upper lines both represent Lizards. The lower line extends to the right, leading to Snakes. The lower line from the first branch point extends downward to the right, reaching a fourth branch point. From this fourth branch point, the upper line extends to the right, leading to Crocodiles, and the lower line extends downward to the right, leading to Birds.

Once the boundaries and number of individuals in a population are determined, populations are often described by their ______ and ______.

The lowest trophic level of a community is the level of ______.

Simpsons Diversity Index is a way to quantify the diversity of a community.  The equation can be written as: D = N(N-1) / ∑ n ( n– 1)  Where: D = Diversity index N = Total number of individuals of all species n = Number of individuals of a specific species   Community A has 3 species (A, B, C). There are 5 individuals of each species. (N=15) Community B has 6 species (A, B, C, D, E). There are 3 individuals each of species A, B, and C. There are 2 individuals each of species D, E, and F. (N=15) Community C has 5 species (A, B, C, D, E). There are 3 individuals each of species. (N=15)   What is the species diversity of Community C?

Evolution on a very small scale can be described as ______

Which of the following factors is the most effective in changing the allele frequency in a natural population?

Reduced hybrid viability is a barrier to speciation that occurs when

Extreme seasonal changes can be mitigated without long-distance moves by