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Science · Drill 14

Science practice 14

11 questions ~9 min recommended
⏱ 00:00
Score
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Fox
Squirrel
Duck
Various
conifers
Various
deciduous
plants
Jaguar
Peccary
Cacti
Grasses
Nutria
Aquatic
plants

Time Series Plot of Jaguar and Peccary
Populations in Shebay Park, 1968-2012
•- Jaguar
- Peccary (in hundreds)
X
1968 1972 1976 1980 1984 1988 1992 1996 2000 2004 2008 2012
Year

Shebay Park has been the site of ongoing population dynamics studies since the 1960s. Consisting of a group of isolated islands, the park provides ecologists with a unique, closed ecosystem in which to analyze the relationship between predator and prey populations. Figure 4.5 illustrates the food web for the Shebay Park ecosystem.

Figure 4.5

Ecological research in the park has focused mainly on the predator-prey relationship between the jaguar and peccary (a type of pig) populations. In addition to the typical selective pressures each species exerts on the other, scientists have observed specific events over the years that have affected population sizes. The inadvertent introduction of feline leukemia by humans in the late 1980s severely reduced the jaguar population. In 2004, the severest winter on record and an outbreak of ticks did the same to the peccary population. Figure 4.6 compares the annual population sizes for both species observed between 1968 and 2012.

Figure 4.6

1. Shebay Park is considered a closed ecosystem because:

2. According to the food web in Figure 4.5, peccary can be categorized as which type of consumer?

3. According to Figure 4.6, what has been the maximum size of the jaguar population since 1968?

4. The peccary population reached its smallest size in which year?

5. It can be inferred that the 13-year trend in the peccary population that began after 1990 was largely influenced by a sharp decline in:

6. According to Figure 4.5, how many secondary consumer species are present in the Shebay Park ecosystem?

7. Organisms that compete for many of the same resources within an ecosystem are said to occupy similar niches. Based on the information in Figure 4.5, which populations occupy a niche most similar to that of the peccary population?

8. Based on the data in Figure 4.6, a sharp decline in a population's size most commonly occurs in response to:

9. Ecologists believe that an increase in parasites is partially responsible for the shift in:

10. Which of the following statements is best supported by the information in the passage?

11. Based on Figure 4.5, which population is least likely to be affected by a change in the peccary population?

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