Our Environment (10 Science)
An ecosystem consists of biotic and abiotic factors interacting in complex food chains and food webs. Understanding energy flow and nutrient cycling is ess
TL;DR: An ecosystem consists of biotic and abiotic factors interacting in complex food chains and food webs. Understanding energy flow and nutrient cycling i…
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An ecosystem consists of biotic and abiotic factors interacting in complex food chains and food webs. Understanding energy flow and nutrient cycling is ess
Our Environment MCQs with Answers & Explanations
Q1. An ecosystem includes:
- Only living organisms
- Only non-living factors
- Both living organisms and non-living factors ✓ (correct)
- Only plants and animals
Q2. In a food chain, plants are called:
- Secondary consumers
- Tertiary consumers
- Producers ✓ (correct)
- Decomposers
Q3. The percentage of energy transferred from one trophic level to the next is approximately:
- 90%
- 50%
- 10% ✓ (correct)
- 25%
Q4. Decomposers in an ecosystem include:
- Plants
- Herbivores
- Carnivores
- Bacteria and fungi ✓ (correct)
Q5. The ozone layer is important because it:
- Produces oxygen
- Traps heat in the atmosphere
- Protects from ultraviolet radiation ✓ (correct)
- Prevents greenhouse gases
Q6. Which of the following is a biotic factor in an ecosystem?
- Temperature
- Sunlight
- Bacteria ✓ (correct)
- Wind
Q7. The carbon cycle involves all of the following EXCEPT:
- Photosynthesis
- Respiration
- Combustion
- Rainfall ✓ (correct)
Q8. Invasive species in an ecosystem can cause:
- Increased biodiversity
- Disruption of native species and food webs ✓ (correct)
- Improved ecosystem balance
- More habitat for organisms
Q9. The primary source of nitrogen for plants is:
- The atmosphere
- Nitrogen-fixing bacteria in soil ✓ (correct)
- Rainwater
- Decomposers
Q10. Which human activity has the most impact on increasing atmospheric CO2?
- Deforestation
- Fossil fuel combustion
- Agricultural practices
- All of the above ✓ (correct)
Frequently Asked Questions
What is biodiversity and why is it important?
Biodiversity refers to the variety of species and genetic variation within an ecosystem. It is important because it maintains ecosystem stability, provides resources for humans, and ensures ecological resilience to environmental changes.
How does pollution affect ecosystems?
Pollution can disrupt food webs by poisoning organisms, reduce biodiversity by making habitats unsuitable, and interfere with nutrient cycles. Bioaccumulation of toxins concentrates pollutants in organisms higher in the food chain.
More 10 Science MCQs
- Light Reflection and Refraction
- Electricity
- Acids Bases and Salts
- Life Processes
- Carbon and its Compounds
- Metals and Non-metals
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