Quiz: Ecosystem Biology and Sustainability — 10 perguntas

1. What is the primary function of photosynthesis in ecosystems?

A. To break down glucose for energy release

B. To absorb nutrients from the soil

C. To convert solar energy into chemical energy stored in glucose

D. To produce oxygen only for animals

Answer: (C)

Explicação

Photosynthesis converts light energy into chemical energy in the form of glucose, which serves as the primary energy source for plants and, indirectly, for other organisms in the ecosystem.

2. What is the approximate efficiency of energy transfer between trophic levels in an ecosystem?

A. 1%

B. 10%

C. 50%

D. 90%

Answer: (B)

Explicação

Energy transfer efficiency between trophic levels is roughly 10%, meaning only about 10% of energy is passed on from one level to the next, with the rest lost mainly as heat.

3. In a food web, approximately what percentage of energy is transferred from one trophic level to the next?

A. 1%

B. 25%

C. 10%

D. 50%

Answer: (C)

Explicação

Typically, about 10% of energy is transferred from one trophic level to the next in a food web, with the rest lost mainly as heat through metabolic processes.

4. Which biogeochemical cycle is primarily involved in converting atmospheric nitrogen into forms usable by plants?

A. Water cycle

B. Carbon cycle

C. Nitrogen cycle

D. Phosphorus cycle

Answer: (C)

Explicação

The nitrogen cycle involves nitrogen-fixing bacteria that convert N₂ from the atmosphere into ammonia, a form that plants can uptake.

5. Which human activity most directly disrupts the nitrogen cycle?

A. Use of pesticides in agriculture

B. Burning fossil fuels

C. Construction of dams

D. Deforestation

Answer: (A)

Explicação

The use of pesticides in agriculture can affect the nitrogen cycle by introducing excess nitrogen compounds into the environment, disrupting natural nitrogen fixation and nitrification processes.

6. Which Earth's layer is directly involved as a habitat for terrestrial organisms and forms the Earth's crust?

A. Core

B. Mantle

C. Lithosphere

D. Atmosphere

Answer: (C)

Explicação

The lithosphere is Earth's outer crust and upper mantle, providing the habitat for terrestrial life, unlike the core or atmosphere.

7. What is a primary characteristic of food webs compared to food chains?

A. Food webs show linear energy transfer

B. Food webs are less complex than food chains

C. Food webs depict complex feeding relationships

D. Food webs ignore multiple pathways of energy flow

Answer: (C)

Explicação

Food webs illustrate complex feeding relationships with multiple pathways, unlike the simple, linear flow shown in food chains.

8. Which of the following greenhouse gases are known to contribute to climate change by trapping heat in Earth's atmosphere?

A. Oxygen (O₂) and Argon (Ar)

B. CO₂, CH₄, N₂O

C. Nitrogen (N₂) and Helium (He)

D. Ozone (O₃) and Hydrogen (H₂)

Answer: (B)

Explicação

Greenhouse gases such as CO₂, CH₄ (methane), and N₂O (nitrous oxide) trap heat in Earth's atmosphere, contributing to climate change.

9. What process do autotrophs, including plants and algae, use to produce organic molecules and oxygen?

A. Cellular respiration

B. Photosynthesis

C. Decomposition

D. Fermentation

Answer: (B)

Explicação

Autotrophs perform photosynthesis, capturing solar energy to synthesize organic molecules like glucose and produce oxygen as a byproduct.

10. Which component of Earth's systems is involved in all water bodies and plays a central role in the water cycle?

A. Biosphere

B. Atmosphere

C. Hydrosphere

D. Lithosphere

Answer: (C)

Explicação

The hydrosphere encompasses all water bodies on Earth and is integral to the water cycle, including processes like evaporation, condensation, and precipitation.