A4.1 - Energy Flow and Cycles

In most ecosystems, the original source of energy for food chains is:

Which group of organisms first changes light energy into chemical energy in food?

A trophic level is best defined as:

Which of the following is TRUE about energy flow in an ecosystem?

Which of these diagrams shows the number of organisms at each trophic level?

Biomass in an ecosystem refers to the:

Which pyramid is usually upright because producers have the greatest mass in an ecosystem?

In the food chain sugar cane → cow → human, which statement best explains why humans receive less energy than the cow?

Which of the following activities in a goat uses energy obtained from the grass it eats?

Which row correctly shows TWO ways energy from food is used by a fish in a Caribbean reef?

Why is a pyramid of biomass usually a better indicator of energy flow than a pyramid of numbers?

In a coastal mangrove, the pyramid of numbers shows one large tree at the base, many insects feeding on the tree, and a few insect-eating birds. The shape of this pyramid of numbers is likely to be:

Which statement about energy transfer is TRUE for both terrestrial and marine food chains?

Which statement best explains why top carnivores like sharks are few in number in marine food webs?

A land ecosystem has the food chain: grass → grasshopper → frog → snake → hawk. Which statement best explains why this chain is unlikely to become much longer?

A pyramid of biomass for a Caribbean seagrass bed shows a very wide base for seagrass and much narrower bars for sea urchins and then snappers. What does this pattern indicate?

A student draws an upright pyramid of numbers for a pasture with many grass plants, a few cows and one farmer. Which change would make the pyramid of numbers more inverted at the bottom?

In the chain phytoplankton → zooplankton → small fish → large fish → shark, which TWO processes account for most of the energy loss between small fish and large fish?

In a simplified reef ecosystem, fishermen remove a large number of snappers (secondary consumers). What is the MOST likely effect on the energy flow and biomass at other levels?

Which statement best links decomposers to energy flow and nutrient recycling in an ecosystem?

A student compares two ecosystems with the same producer biomass. Ecosystem X has long food chains with many top carnivores; Ecosystem Y has short food chains and fewer top carnivores. Which conclusion is MOST consistent with the idea of energy loss along food chains?