🧬 Ecology & Environment — Practice Worksheet

Q1. The term "ecosystem" was coined by:

1. Odum
2. Tansley
3. Haeckel
4. Warming

Q2. In an ecosystem, the flow of energy is:

1. Bidirectional
2. Unidirectional
3. Cyclic
4. Multidirectional

Q3. The 10% law of energy transfer was given by:

1. Odum
2. Lindeman
3. Elton
4. Tansley

Q4. Which of the following is a biodiversity hotspot in India?

1. Thar Desert
2. Western Ghats
3. Gangetic Plain
4. Deccan Plateau

Q5. The pyramid of energy in an ecosystem is always:

1. Inverted
2. Upright
3. Spindle-shaped
4. Variable

Q6. Lichens are an example of:

1. Parasitism
2. Commensalism
3. Mutualism
4. Competition

Q7. The greenhouse effect is primarily caused by:

1. O₂ and N₂
2. CO₂ and CH₄
3. O₃ and Ar
4. H₂ and He

Q8. The process of succession starting on bare rock is called:

1. Hydrosere
2. Xerosere
3. Lithosere
4. Psammosere

Q9. The ozone layer is present in the:

1. Troposphere
2. Stratosphere
3. Mesosphere
4. Thermosphere

Q10. Which of the following is an ex-situ conservation method?

1. National parks
2. Wildlife sanctuaries
3. Botanical gardens and seed banks
4. Biosphere reserves

Q11. The logistic growth equation is represented as:

1. dN/dt = rN
2. dN/dt = rN(K − N)/K
3. dN/dt = rN/K
4. dN/dt = N(K − r)/K

Q12. Biological magnification refers to:

1. Increase in population size
2. Increase in concentration of pollutants at successive trophic levels
3. Increase in biodiversity
4. Increase in biomass at higher trophic levels

Q13. In a food chain: Grass → Grasshopper → Frog → Snake → Hawk, if the grass produces 10,000 J of energy, calculate the energy available to the hawk using the 10% law.

Q14. Differentiate between primary succession and secondary succession with examples. Which one takes longer and why?

Q15. A population of rabbits has a birth rate of 0.5 per capita per year and a death rate of 0.2 per capita per year. If the initial population is 200, calculate the population after one year (assuming exponential growth).

Q16. Explain the carbon cycle with a diagram. What role do oceans play as carbon sinks?

Q17. List and explain three major causes of biodiversity loss. Give one example for each cause.

Q18. Explain the species-area relationship. If the slope (z) is 0.3 and the constant (C) is 100, calculate the number of species expected in an area of 500 sq km (S = CA^z).

Q19. Differentiate between the following ecological interactions with one example each: (a) Mutualism vs Commensalism, (b) Parasitism vs Predation.

Q20. What is eutrophication? Explain its causes, effects on aquatic ecosystems, and two methods to prevent it.