Energy Flow and Nutrient Cycles in Ecosystems

What is the primary source of energy in biological systems?

Sunlight.

How do producers utilize sunlight?

Producers absorb sunlight and convert it to biomass during photosynthesis.

What is the role of decomposers in an ecosystem?

Decomposers break down dead material and waste, returning nutrients to the soil.

What is the order of a food chain?

Producer → Primary Consumer → Secondary Consumer → Tertiary Consumer.

What is a primary consumer?

An organism that eats producers, such as a slug.

What distinguishes herbivores from carnivores?

Herbivores only eat plants, while carnivores eat meat.

What is an omnivore?

An organism that eats both plants and animals.

What percentage of energy is typically lost at each trophic level?

About 90% of energy is lost at each trophic level.

What does the term 'trophic levels' refer to?

The feeding relationships between organisms and the stages of biomass transfer.

What is the carbon cycle?

The process by which carbon compounds are recycled in the ecosystem through photosynthesis, respiration, and decomposition.

How do photosynthetic plants contribute to the carbon cycle?

They remove CO₂ from the atmosphere during photosynthesis.

What happens to carbon compounds when organisms die?

They are decomposed by decomposers, releasing CO₂ back into the atmosphere.

What is the nitrogen cycle?

The process by which nitrogen is recycled in the ecosystem through decomposition, nitrification, and denitrification.

What role do nitrifying bacteria play in the nitrogen cycle?

They convert ammonia into nitrates, which are taken up by plants.

What is bioaccumulation?

The accumulation of toxic substances in organisms at higher trophic levels.

What is eutrophication?

The process where nutrient build-up in water leads to algal blooms, blocking sunlight and depleting oxygen.

What impact does untreated sewage have on water ecosystems?

It increases nutrient levels, leading to algal blooms and oxygen depletion.

What are indicator species?

Species whose presence or absence indicates environmental conditions, such as pollution levels.

How can electronic meters be used in environmental monitoring?

They measure changes in pH or oxygen levels to detect water pollution.

What is the significance of lichens as indicator species?

Lichens can indicate air quality; bushy lichens thrive in cleaner air than crusty lichens.

What is the impact of intensive farming on biodiversity?

Intensive farming reduces biodiversity and disrupts natural habitats.

How do fertilizers affect ecosystems?

Excess fertilizers can lead to nutrient runoff, causing eutrophication.

What are the consequences of using antibiotics in farming?

It can lead to antibiotic resistance in bacteria.

What is the pyramid of numbers (P.O.N)?

It represents the number of organisms per unit area at each trophic level.

What is the pyramid of biomass (P.O.B)?

It illustrates the biomass at each trophic level, typically shaped like a pyramid.

What is the efficiency formula for biomass transfer?

Efficiency = (Biomass available after transfer / Biomass available before transfer) x 100.

What are the main components of the nitrogen cycle?

Decomposition, nitrification, nitrogen fixation, feeding, and denitrification.