Ecological Pyramids and Energy Flow

Mr. Knight introduces ecological pyramids, focusing on energy, biomass, and numbers. He explains how these pyramids compare trophic levels within ecosystems. A sample food chain is used to illustrate the concepts, showing how energy decreases along the chain. The pyramid of biomass is discussed, highlighting the typical decrease in organism numbers up the food chain. An inverted biomass pyramid in aquatic ecosystems is also covered. Finally, the pyramid of numbers is explained, emphasizing its typical shape and the importance of organism count at each level.

What is the primary purpose of ecological pyramids?

• To measure the height of trees in an ecosystem

• To calculate the speed of animal movement

• To compare biological variables between trophic levels

• To determine the age of an ecosystem

In the sample food chain discussed, which organism is the producer?

• Cabbage

• Bird

• Caterpillar

• Rat

Why does energy decrease as it moves up the food chain?

• Energy is lost as heat

• Organisms use energy for their own functions

• Energy is absorbed by the sun

• Energy is stored in the soil

If a cabbage has 1000 kilojoules of energy, how much energy is available to the bird?

• 100 kilojoules

• 10 kilojoules

• 1000 kilojoules

• 1 kilojoule

What is biomass in the context of ecological pyramids?

• The speed of animal movement

• The organic material used as energy or fuel

• The total number of organisms

• The height of the tallest tree

In an aquatic ecosystem, why might a pyramid of biomass be inverted?

• Producers are larger than consumers

• Consumers are microscopic

• Energy is lost at each level

• Producers are microscopic and increase in size up the chain

What shape does a typical pyramid of numbers have?

• Inverted

• Cylindrical

• Upward with a larger base

• Flat

In the pyramid of numbers, what determines the shape of the pyramid?

• The height of the organisms

• The color of the organisms

• The number of organisms at each level

• The speed of energy transfer

In the sample food chain, how many birds are there?

• Four

• Three

• Two

• One

What is a key factor in drawing a pyramid of numbers?

• The color of the boxes

• The relative size of boxes based on organism numbers

• The height of the boxes

• The speed of energy transfer