Ecosystem Energy and Productivity Concepts

Mr. Andersen explains energy flow in ecosystems, highlighting the sun as the primary energy source. He introduces ecological pyramids to illustrate energy loss at each trophic level. Photosynthesis and cellular respiration are detailed, showing how energy is converted and utilized. Chemosynthesis is discussed as an alternative energy system in deep-sea environments. The video also covers energy efficiency and biomass, emphasizing the small percentage of energy transferred between trophic levels. Key points and learning objectives are summarized at the end.

What is the primary source of energy for ecosystems on Earth?

• The Ocean

• The Moon

• The Sun

• Volcanoes

What is an ecological pyramid used to represent?

• The age of ecosystems

• The size of organisms

• The flow of energy

• The number of species

Which process do plants use to convert sunlight into chemical energy?

• Photosynthesis

• Respiration

• Chemosynthesis

• Fermentation

What is the difference between gross and net primary productivity?

• Gross is always higher than net

• Gross includes respiration, net does not

• Net includes respiration, gross does not

• Net is always higher than gross

What are the main products of photosynthesis?

• Glucose and sulfur

• Nitrogen and oxygen

• Oxygen and glucose

• Carbon dioxide and water

How does cellular respiration relate to photosynthesis?

• It is the reverse process

• It occurs only in animals

• It produces the same products

• It uses the same reactants

Which biome is known for having high productivity?

• Savanna

• Tropical rainforest

• Tundra

• Desert

What factor primarily causes changes in productivity over time?

• Animal migration

• Seasons

• Human activity

• Volcanic eruptions

What percentage of energy typically transfers from one trophic level to the next?

• 1%

• 10%

• 50%

• 90%

What role do decomposers play in an ecosystem?

• They increase energy efficiency

• They recycle nutrients

• They consume primary producers

• They produce energy