Question 1

Which of the following best describes the main difference between how energy and matter move through an ecosystem?

Accepted Answer

Energy moves in a one-way path, while matter is recycled through biogeochemical cycles.

Question 2

Which process in the carbon cycle is responsible for removing carbon dioxide from the atmosphere?

Accepted Answer

Photosynthesis

Question 3

What is the balanced chemical equation for cellular respiration?

Accepted Answer

$$C_6H_{12}O_6$ + 6O_2 \rightarrow 6CO_2 + 6H_2O$$

Question 4

Which group of organisms is primarily responsible for breaking down dead plant material in terrestrial ecosystems?

Accepted Answer

Fungi

Question 5

A farmer applies large amounts of fertilizer to his fields, which then runs off into a nearby lake. What is the most likely ecological consequence?

Accepted Answer

Eutrophication, leading to algal blooms and decreased oxygen levels

Question 6

Which of the following is NOT a step in the nitrogen cycle?

Accepted Answer

Photosynthesis

Question 7

Why is phosphorus often a limiting nutrient in aquatic ecosystems?

Accepted Answer

It has no significant gaseous phase and is not easily recycled.

Question 8

Which of the following best explains why deforestation can lead to a change from a tropical rainforest to a semiarid desert?

Accepted Answer

Deforestation disrupts the local water cycle, reducing rainfall and soil moisture.

Question 9

Which of the following is a positive feedback loop related to climate change involving ice and albedo?

Accepted Answer

Climate warming → ice melts → lower surface albedo → more energy absorbed → further warming

Question 10

Which of the following is a correct description of a keystone species?

Accepted Answer

A species whose impact on its community is disproportionately large relative to its abundance.

Question 11

Which of the following chemical equations represents photosynthesis?

Accepted Answer

$$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6$ + 6O_2$$

Question 12

Which of the following is a direct effect of burning fossil fuels on the sulfur cycle?

Accepted Answer

Production of sulfur dioxide ($$SO_2$$), leading to acid rain

Question 13

Which of the following best describes the role of decomposers in the carbon cycle?

Accepted Answer

They break down dead organisms, releasing CO2 back into the atmosphere.

Question 14

Which of the following is an example of an umbrella species?

Accepted Answer

A species whose habitat requirements are so large that protecting it also protects many other species.

Question 15

Which process in the nitrogen cycle returns nitrogen gas ($$N_2) to $$the atmosphere?

Accepted Answer

Denitrification

Question 16

Which of the following is a likely consequence of increased atmospheric CO2 due to human activities?

Accepted Answer

Enhanced greenhouse effect and climate warming

Question 17

Which of the following best explains why the majority of recent extinctions have occurred in the past 150 years?

Accepted Answer

Human activities such as habitat loss, overexploitation, and pollution have accelerated extinction rates.

Question 18

Which of the following is a real-world example of bioremediation?

Accepted Answer

Using bacteria to clean up oil spills in the ocean

Question 19

Which of the following is a characteristic of a biodiversity hotspot?

Accepted Answer

It has a high number of endemic species and has lost at least 70% of its original habitat.

Question 20

Which of the following is a correct sequence of events in the water cycle?

Accepted Answer

Evaporation → condensation → precipitation → runoff

Biogeochemical Cycles and Ecosystem Dynamics

Study Guide - Practice Questions