Ecosystem

EcosystemNEET Botany · Class 12 · NCERT Chapter 5

Overview Notes NEET Questions Interactive Learning

4 interactive concept widgets for Ecosystem. Drag any slider, change any number, and watch the formula and the answer update live. Built so you understand how each NEET problem actually works, not just the final number.

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Energy flow and 10% law simulator

Ecological pyramids explorer (upright vs inverted)

Carbon and phosphorus cycle explorer

Ecosystem: 12-question NEET quiz

Energy flow: 10% law (Lindemann efficiency)

Adjust producer energy and transfer efficiency to trace energy through trophic levels. See why food chains rarely exceed 4 levels and why eating lower in the food chain feeds more people.

Energy Flow

Energy flow: 10% law (Lindemann's efficiency)

Set the producer energy and transfer efficiency to see how energy diminishes at each trophic level. The 10% law means food chains rarely exceed 4 trophic levels.

Producer energy (T1): 10,000 kcal

Transfer efficiency: 10%

Producers (T1)

Plants / Algae

10,000 kcal

Primary consumers (T2)

Herbivores

1,000 kcal

10.0% of T1

Lost: 9,000 kcal

Secondary consumers (T3)

Carnivores

100 kcal

10.0% of T2

Lost: 900 kcal

Tertiary consumers (T4)

Top carnivores

10 kcal

10.0% of T3

Lost: 90 kcal

NEET key facts: energy flow

10% law (Lindemann, 1942): only 10% of energy at one trophic level passes to the next
Remaining 90% is lost as heat (respiration) or goes to decomposers
Energy flow is UNIDIRECTIONAL and NON-CYCLIC (unlike nutrients which cycle)
Food chains rarely exceed 4-5 trophic levels because so little energy remains
Grazing food chain: living plant → herbivore → carnivore
Detritus food chain: dead organic matter → decomposers → detritivores

Try this

With 10,000 kcal at T1 and 10% efficiency: T2 gets 1,000 kcal; T3 gets 100 kcal; T4 gets just 10 kcal. This is why humans eating plants can support 10x more people than humans eating cattle.
Raise efficiency to 20%: this represents some aquatic ecosystems where transfer is more efficient. Reduce to 5% to see why some ecosystems have very short food chains.

Ecological pyramids: number, biomass, and energy

Compare all three pyramid types across grassland, forest/parasitic chain, and marine ecosystems. Discover which pyramids can be inverted and why the energy pyramid is always upright.

Ecological Pyramids

Ecological pyramids: number, biomass, and energy

Switch between pyramid type and ecosystem to see which pyramids can be inverted and why. The energy pyramid is always upright.

Pyramid type:

Pyramid of number

Pyramid of biomass

Pyramid of energy

Ecosystem:

Grassland (upright)

Forest/Parasitic (can invert)

Marine (can invert)

Upright pyramid

Grasses (millions)

Insects (thousands)

Frogs (hundreds)

Hawks (few)

Grassland: upright pyramid of number. Producers (grasses) are most numerous.

NEET key: which pyramids can be inverted?

Pyramid type	Can be inverted?	Example
Number	YES	Parasitic chain (tree → insects → parasites)
Biomass	YES	Marine (phytoplankton < zooplankton standing crop)
Energy	NEVER	Always upright; 10% law ensures energy decreases

Try this

Select "Pyramid of energy" — then try all three ecosystems. It stays upright every time. This is the most-tested fact in NEET about ecological pyramids.
Select "Pyramid of biomass" and "Marine": phytoplankton have LOW standing biomass because they are consumed faster than they accumulate — hence the inverted pyramid.

Nutrient cycles: carbon (gaseous) vs phosphorus (sedimentary)

Explore every step of the carbon and phosphorus cycles. Understand the key distinction NEET tests: carbon has an atmospheric phase; phosphorus is a sedimentary cycle with no gaseous form.

Nutrient Cycling

Nutrient cycles: carbon (gaseous) vs phosphorus (sedimentary)

Click each step of the carbon or phosphorus cycle to see the process, equation, and agents involved. Understand why carbon is a gaseous cycle and phosphorus is a sedimentary cycle.

Carbon cycle

Phosphorus cycle

Gaseous cycle (atmospheric reservoir)

Atmospheric CO2 is the reservoir. Photosynthesis, respiration, decomposition, and combustion are the main processes. Oceans are the largest carbon sink.

Click a step to explore:

CO2 fixation (Photosynthesis)

CO2 release (Respiration)

CO2 release (Decomposition)

CO2 release (Combustion)

Ocean-atmosphere CO2 exchange

Carbon storage (Fossil fuels)

NEET comparison: carbon vs phosphorus

Feature	Carbon cycle	Phosphorus cycle
Type	Gaseous cycle	Sedimentary cycle
Main reservoir	Atmosphere (CO2), oceans	Phosphate rocks, soil
Atmospheric phase	YES (CO2, CH4)	NO (no gaseous form)
Key process in	Photosynthesis, respiration	Weathering, decomposition
Speed	Relatively fast	Slowest of nutrient cycles
Human impact	Fossil fuel CO2 rise	Mining, fertiliser use, eutrophication

Try this

The key NEET distinction: carbon cycle = gaseous (has atmospheric CO2); phosphorus cycle = sedimentary (no atmospheric form). Always asked in NEET.
Click "Fossilisation" in the carbon cycle. Fossil fuels are ancient stored carbon. Burning them releases this carbon in decades, not millions of years, causing the greenhouse effect.

Ecosystem NEET quiz: 12 questions

12-question scored quiz covering ecological pyramids, 10% law, GPP vs NPP, decomposition steps (F-L-C-H-M), energy flow, and nutrient cycling.

Ecosystem

Ecosystem NEET quiz: 12 questions

12-question scored quiz covering ecological pyramids, 10% law, GPP vs NPP, decomposition steps, energy flow, nutrient cycling, and ecosystem services.

Question 1 of 12

Score: 0

Which of the following ecological pyramids is ALWAYS upright, without exception?

Pyramid of number

Pyramid of biomass

Pyramid of energy

Both biomass and number