Ecology Practice Questions
HSC/SSC (Bangladesh) · HSC Biology · 147 free MCQs with instant results and detailed explanations.
147
Total
38
Easy
78
Medium
31
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
Which of the following best describes an ecosystem?
A.
A community of living organisms and their physical environment.
B.
Only the plants in a specific area.
C.
The interactions between different species only.
D.
A group of individuals of the same species.
Show Answer & Explanation
Correct Answer: A
An ecosystem is defined as a community of living organisms interacting with their physical environment, which includes both biotic and abiotic factors.
Q2
Easy
Which of the following is a consequence of habitat destruction?
A.
Increased biodiversity
B.
Species extinction
C.
Improved ecosystem health
D.
Enhanced food supply
Show Answer & Explanation
Correct Answer: B
Habitat destruction leads to the loss of species' natural homes, resulting in decreased population sizes and potential extinction of various species.
Q3
Easy
Which of the following is an abiotic factor in an ecosystem?
A.
Sunlight
B.
Fungi
C.
Plants
D.
Animals
Show Answer & Explanation
Correct Answer: A
Sunlight is an abiotic factor because it is a non-living component that affects the environment and living organisms.
Q4
Medium
Which of the following is an example of a primary consumer in a terrestrial ecosystem?
A.
Grasshopper
B.
Lion
C.
Mushroom
D.
Eagle
Show Answer & Explanation
Correct Answer: A
A grasshopper is a herbivore that directly consumes plants, making it a primary consumer. Lions and eagles are carnivores (secondary consumers), while mushrooms are decomposers.
Q5
Medium
In an aquatic ecosystem, which of the following factors most directly affects the distribution of aquatic plants?
A.
Water temperature
B.
Salinity
C.
Light availability
D.
Nutrient concentration
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Correct Answer: C
Light availability is crucial for photosynthesis in aquatic plants. While water temperature, salinity, and nutrient concentration are important, they affect the growth indirectly, whereas light is essential for their survival.
Q6
Medium
What is the primary role of decomposers in an ecosystem?
A.
To produce food through photosynthesis
B.
To recycle nutrients back into the ecosystem
C.
To compete with primary consumers for food
D.
To provide energy to top predators
Show Answer & Explanation
Correct Answer: B
Decomposers break down dead organic matter, recycling nutrients back into the ecosystem, which is essential for sustaining life. They do not produce food or compete with consumers.
Q7
Medium
Which of the following factors is most likely to increase species diversity in an ecosystem?
A.
Habitat destruction
B.
Invasive species
C.
Environmental stability
D.
Pollution
Show Answer & Explanation
Correct Answer: C
Environmental stability allows various species to thrive and coexist, thus increasing biodiversity. Habitat destruction and pollution reduce diversity, while invasive species can disrupt local ecosystems.
Q8
Hard
In an ecosystem, which of the following factors primarily determines the carrying capacity for a species?
A.
Availability of food and water
B.
Predation pressure
C.
Reproductive rate
D.
Genetic diversity
Show Answer & Explanation
Correct Answer: A
The carrying capacity of an ecosystem for a species is primarily determined by the availability of essential resources like food and water. These resources limit the number of individuals that can survive in a given environment, making option A the most accurate choice.
Q9
Hard
A certain plant species can tolerate a wide range of soil pH levels, ranging from 5 to 8. If the pH level of the soil in an area suddenly shifts to 4, what would most likely happen to this plant species?
A.
The plant will thrive due to increased nutrient availability.
B.
The plant will experience stress and may die.
C.
The plant will adapt to the new pH level immediately.
D.
The plant will grow faster due to reduced competition.
Show Answer & Explanation
Correct Answer: B
A sudden shift in soil pH to 4, which is outside the tolerated range of 5 to 8 for the plant species, would cause stress and potentially lead to the plant's death. Plants require a specific pH range for optimal nutrient uptake, and this drastic change is detrimental.
Q10
Hard
In a certain ecosystem, the energy flow is represented by a pyramid of energy. If the primary producers capture 1000 kcal of energy, what would approximately be the energy available to the secondary consumers, assuming an energy transfer efficiency of 10% per trophic level?
A.
100 kcal
B.
10 kcal
C.
1000 kcal
D.
10,000 kcal
Show Answer & Explanation
Correct Answer: A
In a pyramid of energy, only about 10% of the energy is transferred to the next trophic level. Thus, from 1000 kcal captured by primary producers, only 100 kcal is available for primary consumers, and further only 10% of that (which is 10 kcal) is available for secondary consumers.
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Ecology — HSC/SSC (Bangladesh) HSC Biology Practice Questions Online
This page contains 147 practice MCQs for the chapter Ecology in HSC/SSC (Bangladesh) HSC Biology. The questions are organized by difficulty — 38 easy, 78 medium, 31 hard — so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit.