Ecology Practice Questions
GCSE · GCSE Biology · 146 free MCQs with instant results and detailed explanations.
146
Total
48
Easy
74
Medium
24
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?
A.
The sun
B.
Geothermal heat
C.
Nuclear energy
D.
Wind power
Show Answer & Explanation
Correct Answer: A
The sun is the primary source of energy for nearly all ecosystems because it provides the light energy that plants use to perform photosynthesis, forming the base of the food chain.
Q2
Easy
Which of the following is an abiotic factor in an ecosystem?
A.
Plants
B.
Animals
C.
Soil pH
D.
Fungi
Show Answer & Explanation
Correct Answer: C
Soil pH is an abiotic factor as it is a non-living chemical component of the soil that affects the types of organisms that can thrive in an ecosystem.
Q3
Easy
In a food chain, which organism is typically at the top of the trophic levels?
A.
Producers
B.
Primary consumers
C.
Secondary consumers
D.
Tertiary consumers
Show Answer & Explanation
Correct Answer: D
Tertiary consumers are typically at the top of the trophic levels in a food chain, as they are predators that eat secondary consumers and have no natural predators themselves.
Q4
Medium
Which of the following best describes a food chain?
A.
A linear sequence of organisms through which nutrients and energy pass as one organism eats another.
B.
A complex network of feeding relationships among various organisms in an ecosystem.
C.
A diagram that shows the number of organisms in each trophic level.
D.
A diagram illustrating the types of habitats in an ecosystem.
Show Answer & Explanation
Correct Answer: A
A food chain is defined as a linear sequence where energy and nutrients are transferred from one organism to another, illustrating feeding relationships.
Q5
Medium
In an ecosystem, which of the following roles do decomposers play?
A.
They produce energy through photosynthesis.
B.
They consume primary consumers.
C.
They break down dead organic matter, returning nutrients to the soil.
D.
They compete with plants for sunlight.
Show Answer & Explanation
Correct Answer: C
Decomposers break down dead organic matter, which recycles nutrients back into the soil, making them essential for nutrient cycling in ecosystems.
Q6
Medium
Which of the following factors is most likely to affect the carrying capacity of a habitat?
A.
The number of organisms of the same species present.
B.
The availability of food, water, and shelter.
C.
The type of soil in the habitat.
D.
The seasonal changes in temperature.
Show Answer & Explanation
Correct Answer: B
The carrying capacity of a habitat is determined by the availability of essential resources such as food, water, and shelter, which directly support the survival of organisms.
Q7
Medium
Which of the following statements about biodiversity is true?
A.
Higher biodiversity generally leads to more stable ecosystems.
B.
Biodiversity only refers to the variety of animal species in an area.
C.
Biodiversity does not affect ecosystem services.
D.
Low biodiversity is always beneficial for ecosystem health.
Show Answer & Explanation
Correct Answer: A
Higher biodiversity contributes to ecosystem stability as it increases resilience to changes and disruptions, thus maintaining ecosystem services.
Q8
Hard
In a certain ecosystem, the primary productivity is measured at 2000 kg of biomass per hectare per year. If 10% of this biomass is converted into herbivores and 20% of the herbivores is converted into carnivores, what is the biomass of carnivores per hectare per year?
A.
40 kg
B.
200 kg
C.
400 kg
D.
600 kg
Show Answer & Explanation
Correct Answer: B
The biomass of herbivores is 10% of 2000 kg, which is 200 kg. The carnivores then obtain 20% of this biomass, which calculates to 40 kg. Therefore, the total biomass of carnivores is 200 kg.
Q9
Hard
A scientist studies a population of frogs in a wetland. Over five years, the population shows a consistent doubling each year due to favorable conditions. If the initial population was 50 frogs, what will be the population after 5 years?
A.
400 frogs
B.
800 frogs
C.
1600 frogs
D.
3200 frogs
Show Answer & Explanation
Correct Answer: C
The population doubles each year for 5 years. Therefore, the population can be calculated as 50 * 2^5 = 50 * 32 = 1600 frogs after 5 years.
Q10
Hard
Which of the following best describes the concept of 'carrying capacity' in an ecosystem?
A.
The maximum number of individuals of a species that an ecosystem can support sustainably.
B.
The total biomass of all organisms in a given area.
C.
The number of different species that can coexist in an area.
D.
The rate at which energy is transferred through the food chain.
Show Answer & Explanation
Correct Answer: A
Carrying capacity refers to the maximum population size of a species that an environment can sustain indefinitely without being degraded. This includes factors like resource availability and habitat conditions, making option A the correct choice.
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Ecology — GCSE GCSE Biology Practice Questions Online
This page contains 146 practice MCQs for the chapter Ecology in GCSE GCSE Biology. The questions are organized by difficulty — 48 easy, 74 medium, 24 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.