The graph shows how a Serengeti buffalo population changed over a period of years. During this time period, the buffalo were affected by the rinderpest virus, a debilitating disease with a high mortality (death) rate. However, the virus was eventually eliminated from the population. Population Growth of Serengeti Buffalo 70,000 40,000 50.000 40,000 30.000 20.000 10 12 76 18 20 14 Time (years) Which of the following inferences is supported by the graph? A. The predator population increased in year 16. B. The ecosystem can sustain, at most, 50,000 buffalo. C. The virus was eliminated from the population during year 3. D. The ecosystem is healthiest with a population of 30,000 buffalo.

In 1995, a population of 31 gray wolves was introduced into Yellowstone National Park. The population of the gray wolves fluctuated in the 20-year period after introduction. In 2019 an estimated 80-110 wolves are present in the park. Wolves, elk, and bison are native to Yellowstone, but the wolves disappeared in the 1920s due to excessive hunting. Wolves are primarily carnivores, and elk and bison are primarily herbivores. A team of scientists monitored the population of wolves in Yellowstone for the first 20 years after their release. Number of Individuals 200 180 160 140 120 100 80 60 40 20 0 Number of Individuals Figure 1. Number of Wolves in Yellowstone After Release The scientists also monitored the populations of elk and bison in Yellowstone for the first 20 years after the wolves' release. Figure 2. Number of Elk and Bison in Yellowstone After Wolf Release 16,000 14,000 12,000 10,000 8,000 6,000 4,000 2,000 0 Number of Elk Calves per 100 Adult Females 40 30 2 4 6 8 10 12 14 16…

Barrel cactuses live in the Mexican desert. They are covered in sharp spines. Cactuses can have spines of different lengths. 1. Their sharp spines help protect them from being eaten by bighorn sheep. Cactuses with longer spines are less likely to be eaten by the sheep. The diagrams below show three possible cactus populations. Population 1 龜 龜 1 short Population 2 short 葉養 long Population 3 ...** long, If their environment changes to have many bighorn sheep, which of the following cactus populations will most likely survive?

How did population growth curve with LOW migration compare with the normal population growth curve? How did population growth curve with High migration compare with normal population growth curve?