Food webs and energy transfer eoc review

Which organism receives the least amount of energy from the producers? A. Hawk B. Rabbit C. Grasshopper D. Mouse

A. Hawk Available energy decreases as you go up a food chain or web. Secondary and tertiary consumers receive less energy than primary consumers.

The removal of which of the following groups would cause an immediate decrease in the amount of energy flowing through the system? A. Producers B. Consumers C. Decomposers D. Inorganic nutrients

A. Producers Producers gather energy from the sun and convert it to useable molecules for consumers. Removing producers from any food chain or web will cause an immediate decrease in available energy.

The framework of organic molecules essential to all organisms is composed mainly of carbon atoms. Which processes are involved in the cycling of carbon within an environment? A. photosynthesis and respiration B. evaporation and condensation C. transcription and translation D. diffusion and transpiration

A. photosynthesis and respiration Photosynthesis captures carbon dioxide from the atmosphere and converts it to glucose. Cellular respiration converts glucose to carbon dioxide.

A. Consumers form the bottom levels of both the energy pyramid and the biomass pyramid. B. Producers are at the bottom level of both the energy pyramid and the biomass pyramid. C. Producers are at the bottom of the energy pyramid, but at the top of the biomass pyramid. D. Consumers are at the bottom of the energy pyramid, but at the top of the biomass pyramid.

B. Producers are at the bottom level of both the energy pyramid and the biomass pyramid. Both the biomass pyramid and the energy pyramid have producers at the bottom. Producers account for most of the biomass and most of the available energy in any given ecosystem.

Which will most likely happen if the decomposers are removed from the carbon cycle? A. The amount of carbon dioxide in the atmosphere will increase. B. The amount of carbon dioxide in the atmosphere will decrease. C. The amount of carbon dioxide used by producers will increase. D. The amount of carbon dioxide needed by consumers will decrease.

B. The amount of carbon dioxide in the atmosphere will decrease. Decomposers release carbon into the atmosphere, so if they were removed less carbon would reach the atmosphere.

In a process called transpiration, plants get rid of excess water through pores in the leaves called stomata. This excess water is then released into the atmosphere as part of the water cycle. Which of the following terms best describes how the released water enters the atmosphere? A. condensation B. precipitation C. evaporation D. capillary action

C. evaporation Water that is released by plants through transpiration evaporates into the atmosphere to rejoin the water cycle.

Which of these organisms would most likely be found at the top of an energy pyramid? A. clams - a primary consumer B. sardines - a primary consumer C. sharks - a secondary consumer D. kelp - a primary producer

C. sharks - a secondary consumer Energy pyramids show the amount of available energy with the lowest levels having the most energy. Producers are found at the bottom of the pyramid, while secondary consumers would be found at the top.

Complete burning of plant material returns carbon primarily to the A. herbivores. B. water. C. vegetation. D. atmosphere.

D. Atmosphere When plant material is burned, carbon is released as carbon dioxide, which enters the Earth's atmosphere.

Which of the following best explains the difference in the amount of available energy in the trophic levels of the desert ecosystem? A. There is less energy available in the producers because their tissues are less dense than those at higher trophic levels. B. There is more energy available in the second trophic level because less energy is needed for hunting compared to the higher trophic levels. C. There is more available energy in the birds of prey because they have greater muscle mass for storing energy than organisms in lower trophic levels have. D. There is less available energy in the fourth trophic level because of the loss of energy through metabolism in each of the lower trophic levels.

D. There is less available energy in the fourth trophic level because of the loss of energy through metabolism in each of the lower trophic levels. Each successive trophic level contains about 10% of the available energy from the previous trophic level. The other 90% is lost as heat to the atmosphere through metabolism by the organisms in that level.