End of Unit Test Energy flow and Human Impact

What is the primary source of energy in biological systems?

• The sun

• Chemical reactions

• Geothermal energy

• Nuclear energy

Which process allows plants to get their energy directly from the sun?

• Photosynthesis

• Respiration

• Transpiration

• Digestion

A food chain is

• A process of photosynthesis

• A sequence showing how each living thing gets its food

• A type of ecosystem

• A method of food preservation

A food web is a complex network of interconnected food chains in an ecosystem. What does a food web represent?

• The flow of energy and nutrients through different organisms

• The migration patterns of animals in search of food and resources

• The water cycle in an ecosystem

• The process of photosynthesis

Where is energy lost in a food chain?

• At each trophic level

• Only at the producer level

• Only at the consumer level

• Energy is not lost

How much energy is transferred to the next level in a food chain?

• 10%

• 20%

• 30%

• 40%

What are the effects of the loss of energy in a food chain?

• It leads to an increase in the number of predators.

• It causes a decrease in the population of organisms at higher trophic levels.

• It results in more energy being available for primary producers.

• It has no impact on the ecosystem.

How would a carbon atom in you appear as a carbon atom of a glucose molecule in the leaf of a plant?

• Through photosynthesis

• By cellular respiration

• Via transpiration

• Through nitrogen fixation

What happens to the concentration of oxygen in the atmosphere due to combustion of fossil fuels?

• Oxygen will decrease as combustion uses up oxygen.

• Oxygen will increase as combustion releases oxygen.

• Oxygen concentration remains unchanged.

• Oxygen is converted into another element.

What happens to the concentration of carbon dioxide in the atmosphere due to combustion of fossil fuels?

• Carbon dioxide will increase greatly as combustion releases the carbon in fossil fuels as carbon dioxide.

• Carbon dioxide will decrease as it is absorbed by plants.

• Carbon dioxide will remain the same as it is balanced by natural processes.

• Carbon dioxide will convert into oxygen.