Which of the following must be considered to determine the species diversity of a community?

A) the time of year when a bird species mates and the location of their nests
B) the number of different plant species found in a community
C) whether competitive exclusion has taken place
D) the number of each type of plant species in a community
E) both species richness and relative abundance


Which of the following is clearly a case of density-dependent population regulation?
A) the drought-induced drying of savanna grass for an insect that feeds on grass sap
B) a dangerous new flu strain transmitted among humans by sneezing
C) the first hard frost of fall for a population of morning glory vines
D) the occurrence of rainstorms for an opportunistic desert annual
E) all of the above