Q: A population of rabbits in a field grows according to the exponential growth equation $$dN/dt = r$$_{max}$$N. If$$ $$r_{max} = 0.2$$ and the current population size $$N = 500$$, what is the expected change in population size per unit time?

$$dN/dt = 0.2 \times 500 = 100$$

Question 1

Which of the following best describes how endotherms and ectotherms differ in their strategies for regulating body temperature?

Accepted Answer

Endotherms use thermal energy generated by metabolism to maintain homeostatic body temperatures, while ectotherms regulate temperature behaviorally.

Question 2

A population of rabbits in a field grows according to the exponential growth equation $$dN/dt = r$$_{max}$$N. If$$ $$r_{max} = 0.2$$ and the current population size $$N = 500$$, what is the expected change in population size per unit time?

Accepted Answer

$$dN/dt = 0.2 	imes 500 = 100$$

Question 3

Which of the following is an example of a density-dependent factor affecting population growth?

Accepted Answer

A disease spreading more rapidly as population density increases

Question 4

A community contains 3 species with the following numbers: 10, 20, and 70 individuals. Using the Simpson's Diversity Index formula $$D = 1 - \sum \left( \frac{n}{N} \$$right)^2$$, what is the diversity index for this community?

Accepted Answer

$$D = 1 - [(0.1)^2$ + (0.2)^2$ + (0.7)^2$] = 1 - [0.01 + 0.04 + 0.49] = 1 - 0.54 = 0.46$$

Question 5

Which of the following best explains why keystone species are critical to ecosystem stability?

Accepted Answer

Their effects on ecosystem structure are disproportionate to their abundance.

Question 6

Which of the following is a real-world example of a behavioral response that increases an organism's fitness?

Accepted Answer

A bird performing a mating dance to attract a mate

Question 7

If a population's growth is described by the logistic growth equation $$dN/dt = r$$_{max}$$N \left( \frac{K-N}{K} \right)$$, what happens as $$N$$ approaches $$K$$?

Accepted Answer

The population growth rate slows and approaches zero.

Question 8

Which of the following best describes the impact of invasive species on native ecosystems?

Accepted Answer

They often outcompete native species for resources, leading to ecological changes.

Question 9

Which of the following is an example of mutualism?

Accepted Answer

Bees pollinating flowers while collecting nectar

Question 10

A population of fish in a lake is initially 200. In one year, 50 are born and 30 die. Using the population growth equation $$dN/dt = B - D$$, what is the population change?

Accepted Answer

$$dN/dt = 50 - 30 = 20$$

Question 11

Which of the following best explains why ecosystems with higher biodiversity are more resilient to environmental changes?

Accepted Answer

They contain a greater variety of species that can fill ecological roles if others are lost.

Question 12

Which of the following is a correct statement about the flow of energy in an ecosystem?

Accepted Answer

Autotrophs capture energy from the environment, and heterotrophs obtain energy by consuming other organisms.

Question 13

Which of the following is an example of a density-independent factor?

Accepted Answer

Flooding

Question 14

Which of the following best describes the relationship between metabolic rate and body size in multicellular organisms?

Accepted Answer

Smaller organisms have higher metabolic rates per unit body mass.

Question 15

Which of the following is a likely consequence of removing a keystone species from an ecosystem?

Accepted Answer

The ecosystem often collapses or undergoes dramatic changes.

Question 16

Which of the following is an example of a physiological response to an environmental change?

Accepted Answer

A human sweating to cool down during exercise

Question 17

Which of the following best describes the effect of a decrease in producer biomass on an ecosystem?

Accepted Answer

It decreases the number and size of higher trophic levels.

Question 18

Which of the following is true about mutations in populations?

Accepted Answer

Mutations are random and can provide genetic variation for selection.

Question 19

Which of the following is an example of a trophic cascade?

Accepted Answer

The removal of wolves from Yellowstone leading to an increase in deer and a decrease in vegetation.

Question 20

Which of the following human activities is most likely to accelerate changes in ecosystem structure and dynamics?

Accepted Answer

Introducing a new disease to a region

AP Biology Unit 8: Ecology – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards