Ecosystem Interactions and Energy Flow

Miss Hamill explains ecosystems, focusing on their stability, abiotic and biotic factors, and the roles of autotrophs and heterotrophs. She discusses food chains, webs, and energy flow, highlighting the inefficiency of energy transfer. The video covers energy and biomass pyramids, symbiotic relationships like mutualism, commensalism, and parasitism, and nutrient cycles involving carbon, oxygen, water, and nitrogen. The lecture concludes with a call to action for environmental responsibility.

What are the three conditions necessary for an ecosystem to maintain stability?

• High biodiversity, predators, and prey

• Constant energy supply, autotrophs, recycling of materials

• Stable climate, abundant water, and sunlight

• Presence of decomposers, herbivores, and carnivores

Which of the following is an example of an abiotic factor in an ecosystem?

• Predators

• Plants

• Temperature

• Decomposers

What is the primary role of autotrophs in a food chain?

• To act as top predators

• To decompose dead matter

• To produce organic molecules from inorganic substances

• To consume other organisms

Which type of consumer only eats plants?

• Carnivores

• Omnivores

• Herbivores

• Scavengers

In an energy pyramid, why is there less energy available at higher trophic levels?

• Energy is created at higher levels

• Higher levels have more organisms

• Producers consume more energy

• Energy is lost as heat and through maintaining homeostasis

What is the relationship called when both organisms benefit from their interaction?

• Commensalism

• Parasitism

• Predation

• Mutualism

Which cycle involves the conversion of nitrogenous waste into usable material for plants?

• Nitrogen cycle

• Oxygen cycle

• Water cycle

• Carbon cycle

What is the role of decomposers in an ecosystem?

• To produce energy from sunlight

• To act as primary consumers

• To consume living plants

• To break down dead or decaying matter

Which of the following is an example of commensalism?

• Barnacles on a whale

• A tapeworm in a human

• A lion hunting a zebra

• A bee pollinating a flower

What process in the water cycle involves the movement of water through a plant?

• Respiration

• Evaporation

• Condensation

• Transpiration