Chapter 12: Ecosystem — Online MCQ Test
BIOLOGY · Grade 12 · CBSE(NCERT)
Practice Chapter 12: Ecosystem with a free chapter-wise online MCQ test.
This chapter covers: Ecosystem Biotic Components Abiotic Components Food Chain Food Web Energy Flow Ecological Pyramid Primary Productivity Decomposition Nutrient Cycling Biomass.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 12: Ecosystem — Important Questions & Answers
Which of the following is an abiotic component of an ecosystem?
- A. Producers
- B. Decomposers
- C. Temperature
- D. Consumers
Answer: C. Temperature
Abiotic components are non-living factors such as temperature, light, water and soil. Producers, consumers and decomposers are biotic components.
Abiotic components are non-living factors such as temperature, light, water and soil. Producers, consumers and decomposers are biotic components.
The vertical distribution of different species occupying different levels in an ecosystem is called:
- A. Stratification
- B. Decomposition
- C. Mineralisation
- D. Leaching
Answer: A. Stratification
Stratification refers to the vertical layering of organisms, such as trees, shrubs and herbs in a forest ecosystem.
Stratification refers to the vertical layering of organisms, such as trees, shrubs and herbs in a forest ecosystem.
If the gross primary productivity of an ecosystem is 1200 kcal m−2 yr−1 and respiration loss is 500 kcal m−2 yr−1, what is its net primary productivity?
- A. 500 kcal m−2 yr−1
- B. 700 kcal m−2 yr−1
- C. 1200 kcal m−2 yr−1
- D. 1700 kcal m−2 yr−1
Answer: B. 700 kcal m−2 yr−1
NPP = GPP - R. Therefore, NPP = 1200 - 500 = 700 kcal m−2 yr−1.
NPP = GPP - R. Therefore, NPP = 1200 - 500 = 700 kcal m−2 yr−1.
A forest has many plant layers such as tall trees, smaller trees, shrubs and herbs. This is an example of:
- A. Nutrient leaching
- B. Stratification
- C. Humification
- D. Energy loss
Answer: B. Stratification
Vertical layering of vegetation in a forest is called stratification, a structural feature of ecosystems.
Vertical layering of vegetation in a forest is called stratification, a structural feature of ecosystems.
Which statement about the carbon cycle and phosphorus cycle is correct?
- A. Both have atmosphere as their main reservoir
- B. Carbon cycle is sedimentary and phosphorus cycle is gaseous
- C. Carbon has a major atmospheric component, while phosphorus mainly cycles through rocks and sediments
- D. Phosphorus is released in large amounts through respiration like carbon dioxide
Answer: C. Carbon has a major atmospheric component, while phosphorus mainly cycles through rocks and sediments
Carbon cycling involves the atmosphere mainly as carbon dioxide, while phosphorus has its major reservoir in rocks and sediments.
Carbon cycling involves the atmosphere mainly as carbon dioxide, while phosphorus has its major reservoir in rocks and sediments.