Biology: The Biosphere: Earth's Life-Supporting Systems Worksheet

Question 1

Define the biosphere in your own words. Include at least two examples of places where living things can be found.

Accepted Answer

The biosphere is the part of Earth where life exists. It includes places such as forests, oceans, soil, lakes, and even areas high in the atmosphere where tiny organisms or spores may be found.

Question 2

Name the four major Earth systems and briefly describe how each one helps support life.

Accepted Answer

The atmosphere provides gases such as oxygen and carbon dioxide and helps regulate temperature. The hydrosphere provides water. The geosphere provides land, soil, and minerals. The biosphere includes all living things and their interactions.

Question 3

A pond ecosystem includes fish, algae, insects, mud, sunlight, water, oxygen, and bacteria. Sort these items into biotic and abiotic factors.

Accepted Answer

The biotic factors are fish, algae, insects, and bacteria because they are living or were once living. The abiotic factors are mud, sunlight, water, and oxygen because they are nonliving parts of the ecosystem.

Question 4

Explain how energy usually enters most ecosystems and how it moves through a food chain.

Accepted Answer

Energy usually enters most ecosystems as sunlight. Producers such as plants or algae use sunlight to make food, and then energy moves to consumers when they eat producers or other consumers.

Question 5

Write a food chain with at least four parts that could exist in a grassland ecosystem. Label the producer and the consumers.

Accepted Answer

One possible food chain is grass to grasshopper to frog to hawk. The grass is the producer, and the grasshopper, frog, and hawk are consumers.

Question 6

Why are decomposers important in the biosphere? Give one example of a decomposer.

Accepted Answer

Decomposers are important because they break down dead organisms and wastes, returning nutrients to the soil or water. An example of a decomposer is a fungus, bacterium, or earthworm.

Question 7

Describe one way the atmosphere and biosphere interact.

Accepted Answer

The atmosphere and biosphere interact when animals breathe oxygen from the air and release carbon dioxide. Plants also take in carbon dioxide from the atmosphere and release oxygen during photosynthesis.

Question 8

Describe one way the hydrosphere and biosphere interact.

Accepted Answer

The hydrosphere and biosphere interact because living things need water to survive. For example, fish live in water, and land plants absorb water through their roots.

Question 9

A forest is cut down to build homes. Identify two possible effects this change could have on the local biosphere.

Accepted Answer

Cutting down a forest can remove habitats, causing some animals to move away or die. It can also reduce the number of plants that produce oxygen, store carbon, and help prevent soil erosion.

Question 10

Explain why biodiversity can make an ecosystem more stable.

Accepted Answer

Biodiversity can make an ecosystem more stable because many different species can fill different roles. If one species decreases, other species may still provide food, pollination, decomposition, or other important functions.

Question 11

Use the water cycle to explain how water moves between the hydrosphere, atmosphere, geosphere, and biosphere.

Accepted Answer

Water evaporates from oceans, lakes, and soil into the atmosphere. It falls as precipitation onto land and water, soaks into the ground, and is used by plants and animals. Plants can also release water vapor back into the atmosphere through transpiration.

Question 12

Carbon moves through Earth's systems. Describe how carbon can move from the atmosphere into the biosphere and then back into the atmosphere.

Accepted Answer

Carbon can move from the atmosphere into the biosphere when plants take in carbon dioxide during photosynthesis. It can move back into the atmosphere when organisms respire, when decomposers break down dead matter, or when materials burn.

Question 13

A drought affects a lake ecosystem. Predict how the drought could affect producers, consumers, and abiotic factors in the lake.

Accepted Answer

A drought could lower the water level and increase water temperature, which are abiotic changes. Producers such as algae and aquatic plants may have less habitat or fewer nutrients. Consumers such as fish, insects, and birds may have less food, less oxygen, or less space to live.

Question 14

Compare a habitat and a niche. Use an example of an organism in your explanation.

Accepted Answer

A habitat is the place where an organism lives, while a niche is the role the organism has in its ecosystem. For example, a bee's habitat may be a meadow, and its niche includes collecting nectar and pollinating flowers.

Question 15

A student says, "Humans are separate from the biosphere because we use technology." Explain why this statement is incorrect.

Accepted Answer

This statement is incorrect because humans are living organisms and are part of the biosphere. Humans depend on Earth's systems for air, water, food, materials, and a stable climate, even when they use technology.

Biology: The Biosphere: Earth's Life-Supporting Systems

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