Laws of Conservation

The total energy of a system remains constant, regardless of changes within the system.

• Carnivore

• Herbivore

• Food webs

• Laws of conservation of mass and energy

The law of conservation of energy states that ____

• energy can only be destroyed.

• energy can only be created.

• energy cannot be created nor destroyed.

• energy cannot be created but can be destroyed.

Which observation shows that living systems follow the law of conservation of mass?

• Living animals must consume food with a mass much greater than the mass of their body over their lifetime.

• Most plants and animals begin their life cycle with a smaller mass and gain mass during development.

• The total mass of all organisms in an ecosystem remains the same over time.

• The total mass of a dead organism equals the total mass of matter released to the environment by decomposition.

Joseph has a terrarium. It is a sealed container with plants and animals. Inside the container, the plants and animals grow and reproduce. From time to time, Joel puts the terrarium on a balance and gets the same reading, 1525.3 grams.

This best supports which law of living systems?

• Law of conservation of energy

• Law of conservation of mass

• Law of motion

• Law of life

During photosynthesis, plants take in carbon dioxide, water, and energy from the sun and produce carbohydrates and oxygen. Which of the following statements best explains how plants follow the law of conservation of mass during photosynthesis?

• The number of carbon dioxide molecules taken in exactly equals the number of carbohydrate molecules produced.

• The amount of each element in the reactants equals the amount of each element in the products.

• The plants mass does not increase or decrease as a result of photosynthesis.

• The plant uses the carbon dioxide gas, liquid water, and energy to produce a solid carbohydrate.

What is the ultimate source of energy for ecosystems?

• consumers

• decomposers

• the sun

• producers

During the process of living and growing, which of the following occurs in all living things?

• Energy changes from one form to another.

• Energy is completely used up.

• Energy is both created and destroyed.

• Energy is converted to mass.

The law of conservation of energy states that energy cannot be created nor destroyed – it can only change form or be transferred? Which of the following supports the law of conservation of energy found in all living systems?

• Decomposers transfer energy stored in the molecules of the dead organism to create new biomass for other organisms to feed on.

• Most plants and animals begin their life cycle with small energy needs and gain more requirements as they develop.

• The total mass of dead organism equals the total mass of matter released to the environment by decomposition.

• The total energy of all organisms is an ecosystem remains the same over time.

The diagram provided shows the carbon and nitrogen flow through a man-made mussel bed in the ocean. What evidence would support the law of conservation of mass for this ecosystem?

• The amount of carbon and nitrogen removed during the harvest equals the amount seeded as biomass.

• The total amount of carbon and nitrogen entering the ecosystem equals the total amount leaving the ecosystem.

• Carbon and nitrogen enter and leave the ecosystem only through man-made processes.

• The mass of scavengers, decomposers, and feces equals the mass absorbed from phytoplankton and detritus.

The law of conservation of mass states that ___

• matter can neither be created nor destroyed.

• matter can only be destroyed.

• matter can only be created.

• matter can be created or destroyed.