Ecology Practice Questions
Thanaweya Amma (Egypt) · Thanaweya Biology · 147 free MCQs with instant results and detailed explanations.
147
Total
41
Easy
76
Medium
30
Hard
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Sample Questions from Ecology
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
What is the primary source of energy for nearly all ecosystems on Earth?
A.
The Moon
B.
The Sun
C.
Geothermal energy
D.
Wind energy
Show Answer & Explanation
Correct Answer: B
The Sun is the primary source of energy for almost all ecosystems because it provides the light needed for photosynthesis, which is the foundation of food webs.
Q2
Easy
Which of the following is an example of a biotic factor in an ecosystem?
A.
Temperature
B.
Water
C.
Plants
D.
Soil pH
Show Answer & Explanation
Correct Answer: C
Plants are a biotic factor as they are living organisms that interact with other organisms in an ecosystem, unlike abiotic factors which include non-living components.
Q3
Easy
What is the primary source of energy for most ecosystems?
A.
Sunlight
B.
Water
C.
Soil nutrients
D.
Wind
Show Answer & Explanation
Correct Answer: A
Sunlight is the primary source of energy for most ecosystems as it drives photosynthesis in plants, which is the foundation for energy flow in ecological food webs.
Q4
Medium
Which of the following best describes the term 'biome'?
A.
A specific ecosystem with unique species.
B.
A large area characterized by its climate and vegetation.
C.
A group of organisms of the same species.
D.
A process by which organisms interact with each other.
Show Answer & Explanation
Correct Answer: B
A biome is defined as a large ecological area on the Earth's surface, with flora and fauna (plants and animals) adapting to their environment. It is primarily characterized by its climate and vegetation types.
Q5
Medium
In a food chain, which of the following organisms would be classified as a primary consumer?
A.
Grass
B.
Rabbit
C.
Fox
D.
Eagle
Show Answer & Explanation
Correct Answer: B
A primary consumer is an organism that eats producers (like plants). In this case, the rabbit feeds on grass, which qualifies it as a primary consumer in the food chain.
Q6
Medium
What is the primary role of decomposers in an ecosystem?
A.
To produce food through photosynthesis.
B.
To convert organic matter into inorganic nutrients.
C.
To compete with plants for sunlight.
D.
To provide shelter for other organisms.
Show Answer & Explanation
Correct Answer: B
Decomposers play a crucial role in ecosystems by breaking down dead organic material and returning inorganic nutrients to the soil, thus facilitating nutrient cycling and supporting plant growth.
Q7
Medium
Which of the following factors is considered a density-dependent limiting factor for a population?
A.
Natural disasters
B.
Food availability
C.
Temperature changes
D.
Wildfires
Show Answer & Explanation
Correct Answer: B
Density-dependent limiting factors are those that have an increasing effect as the population density rises. Food availability directly impacts the survival and reproduction of organisms as their population grows.
Q8
Hard
In a certain ecosystem, the primary productivity is measured to be 5000 kcal/m²/year. If the efficiency of energy transfer between trophic levels is approximately 10%, what is the expected energy available to the secondary consumers?
A.
500 kcal/m²/year
B.
1000 kcal/m²/year
C.
250 kcal/m²/year
D.
400 kcal/m²/year
Show Answer & Explanation
Correct Answer: B
The energy available to secondary consumers can be calculated by taking 10% of the energy available to primary consumers. This means 10% of 5000 kcal/m²/year gives 500 kcal/m²/year to primary consumers and then taking 10% of that results in 1000 kcal/m²/year for secondary consumers.
Q9
Hard
Consider a habitat where the population of species A increases significantly while species B decreases. If species A is a predator of species B, what ecological principle is illustrated by this situation?
A.
Carrying capacity
B.
Trophic cascade
C.
Competitive exclusion
D.
Biomagnification
Show Answer & Explanation
Correct Answer: B
This scenario illustrates a trophic cascade, where the increase in a predator species (A) negatively impacts the prey species (B), leading to a decrease in its population. This shows the interdependence of species in an ecosystem.
Q10
Hard
In a certain ecosystem, the primary productivity is measured at 2000 g/m²/year. If the respiration rate of the producers is 800 g/m²/year, what is the net primary productivity (NPP) of this ecosystem?
A.
1200 g/m²/year
B.
800 g/m²/year
C.
2000 g/m²/year
D.
3000 g/m²/year
Show Answer & Explanation
Correct Answer: A
Net primary productivity (NPP) is calculated by subtracting the respiratory losses from the gross primary productivity (GPP). Here, NPP = GPP - respiration = 2000 g/m²/year - 800 g/m²/year = 1200 g/m²/year.
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Ecology — Thanaweya Amma (Egypt) Thanaweya Biology Practice Questions Online
This page contains 147 practice MCQs for the chapter Ecology in Thanaweya Amma (Egypt) Thanaweya Biology. The questions are organized by difficulty — 41 easy, 76 medium, 30 hard — so you can choose the right level for your preparation.
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