MCQs on Ecology

Ecology is the study of the relationship between the environment and organisms. It deals with topics such as population, food scarcity, pollution and global warming, extinction of various organisms, etc. Moreover, it deals with the fields of evolution, physiology, genetics, etc. In a nutshell, any form of biodiversity comes under ecology.

Before answering the MCQs of ecology and ecosystem, let us revise some of the important points of the ecosystem. An ecosystem is a geographical region in which plants, animals, and other species, as well as weather and topography, interact and coexist. Ecosystems comprise both biotic and abiotic elements, or living and nonliving components. Plants, animals, and other species are examples of biotic factors. Rocks, temperature, and humidity are examples of abiotic variables. In simpler terms, an ecosystem is made up of a group of species and their physical surroundings. Ecosystems can be classified into marine or aquatic and terrestrial in nature. Biomes are the term used for broad classifications of terrestrial ecosystems. An important point to note is that ecosystems with more biodiversity are more stable, having more resistance and resilience to shocks and disruptive events.

This article comprises some important MCQ on ecology, which will help you to score better in the exams. Additionally, you will get a better understanding of the subject. The answers to this environment and ecology objective questions are given at the end for reference.

MCQ on Ecology

1. The natural residence of every organism is known as:

1. Biome

2. Niche

3. Habit

4. Habitat

Ans- Habitat

Explanation- In ecology, the term habitat is used to refer to the collection of resources, physical and biological factors. An important defining feature is that organisms can reproduce and survive in the given area.

2. What is the name of the feature that allows organisms to survive in the conditions of their habitat?

1. Adjustment

2. Adaptation

3. Acclimatization

4. Adaptive variation

Ans- Adaptation

Explanation-  Adaptation is the method of adjusting to new habitats or changes in their existing environment, according to evolutionary theory; it is the outcome of natural selection acting on heritable variation over generations.

3. Shelford’s law of tolerance is named after:

1. James Shelford.

2. Jacob Shelford

3. Ernest Shelford

4. None of these

Ans- Ernest Shelford

Explanation- Victor Ernest Shelford discovered Shelford's law of tolerance in 1911. It claims that an organism's success is determined by a complicated set of circumstances, with each organism having a specific minimum, maximum, and optimal environmental factor or combination of variables that determine success.

4. Shelford’s law of tolerance suggests that organisms with a wide tolerance limit for environmental factors show:

1. Narrow distribution with low population

2. Wide distribution with high population 

3. Wide distribution with high population 

4. Narrow distribution with high population

Ans- Wide distribution with high population 

Explanation- According to the law species that are able to withstand high stress usually have a greater area of distribution and large population. 

5. A wide variety of living organisms is called:

1. Biodiversity 

2. Population

3. Habitat

4. Diversity

Ans- Biodiversity 

Explanation- It is the term in ecology which is used to define the flora and fauna population in a particular area. 

6. Animal adopts a similar state like sleep to reduce their metabolic rate, it is called:

1. Migration

2. Transpiration

3. Hibernating

4. None of these

Ans- Hibernating

Explanation- Hibernation is a strategy for animals to store energy in order to withstand harsh weather or a shortage of food. Physiological changes such as a reduction in body temperature and a reduced metabolism are commonly involved in the process.

7. Hyenas and Vultures are ________________.

1. Omnivorous 

2. Scavengers

3. Carnivorous

4. Herbivorous

Ans- Scavengers

Explanation- Scavengers are the animals that feed on the dead and rotting organisms. Scavengers provide an important service to the ecosystem by removing disintegrating organisms and acting as an innate sanitation system. Scavengers assist conserve energy and nutrients received from rotting flesh within the top trophic levels and thus are capable of transferring the energy and nutrients further away from the source of the carrion.

8. A mutual relationship between two organisms, where both of them are benefitting from watching the other is called:

1. Mutualism

2. Symbiosis

3. Parasitism

4. Food chain

Ans- Mutualism

Explanation- Mutualism is defined as an interspecies interaction that has a favourable influence on the participating species' per capita reproduction and/or survivability. 

9. Which is not a feature of heliophyte among the following?

1. Stem with long internodes

2. Numerous rootlets

3. Long lateral roots

4. Vigorous fruiting and flowering

Ans- Stem with long internodes

Explanation- Heliophytes are heat resistant plants. They are adapted to an environment with high levels of insolation. Coarse, small leaves with hairy and waxy protection against excessive solar radiation and water loss are unique to the plant. The leaves have a lot of double palisade layers in their structure.

10. Which of the following is not a feature of ‘r’ selected species?

1. Reproduce quickly

2. The low survival rate of progenies

3. Reproduce a large number of progenies

4. Paternal care

Ans- Paternal care

Explanation- ‘r’ selected species does not provide paternal care to the filial generations, the species belonging to this category are small animals like mice and flies. The defining trait of r-selected species is the generation of small progeny accompanied by exponential population expansion. 

Additionally, these are some common multiple-choice questions in ecology with answers that students can follow for better grades.

MCQ on Ecosystem

Let us look into some of the MCQs for a better understanding of the concept. 

1. The term ecosystem was proposed by ________________ .

1. Lindeman

2. AG  Tansley

3. Grinnel

4. Turesson

Ans- AG  Tansley, 

Explanation- AG  Tansley, coined the term ecology in 1935. Tansley defined the term as a unit where all ta abiotic factors interacted in the environment. These biotic and abiotic factors are joined together through nutrient cycles and energy flows. Ecology is the study of organisms and their interactions with their surroundings. An ecologist is a scientist who investigates the interactions between living things and their environments.

2. What percentage of oxygen and carbon dioxide exists in the ecosystem?

1. 20.95% and 0.004%

2. 20.95% and 0.04% 

3. 20.0% and 0.40%

4. 20.0% and 0.44%

Ans- 20.95% and 0.04%

Explanation- Oxygen and carbon dioxide is the major gases of the earth’s atmosphere. Nitrogen is the most abundant gas in the atmosphere, it constitutes about 78 % of the total concentration of gases in the atmosphere.

3. Which of the following is the smallest artificial ecosystem that has been sustained for a long period?

1. Folsom pond

2. Folsom bottle

3. Folsom stream

4. None of these

Ans- Folsom bottle 

Explanation- Folsom bottles are self-sustaining artificial ecosystems.

4. ________ is a group of species exploits the biotic and abiotic resources in the same way.

1. Community

2. Ecads

3. Biomes

4. Guild

Ans- Guild

Explanation - A guild is a collection of organisms that share resources or exploit diverse resources in similar ways. Sharing an ecological niche is not a requirement of the guild.

5. Which is/are the abiotic components of an ecosystem?

1. Soil

2. Protein

3. Carbon

4. All of the above

Ans- All of the above 

Explanation- abiotic components of the ecosystem include all the non-living things of an ecosystem. It constitutes gases, water vapour, rocks and soils of the ecosystem.   

6. The set of ecosystems is called ______________.

1. Atmosphere

2. Hydrosphere

3. Biome

4. None of the above

Ans- Biome

Explanation- Biome is the collective term used to define an ecosystem on a planetary level. Biomes consist of larger climatic zone having vegetation and associated fauna.

MCQ on Environmental Science

The additional questions of environmental sciences will help students develop a precise understanding of the concept. 

1. Acid rain is a result of:

1. Excess amount CO₂

2. Excess amount of NH₃

3. Excess amount of SO₂ and NO₂

4. Excess carbon monoxide

Ans- Excess amount of SO₂ and NO₂

Explanation- Acid rain, also known as acid deposition, is a general phrase that refers to any type of precipitation that contains acidic compounds, such as sulfuric or nitric acid, This can include acidic rain, snow, fog, hail, or even dust.

2. The greenhouse effect in the atmosphere is produced due to:

1. Absorption and re-emission of infrared radiation by the atmosphere

2. Absorption and re-emission of ultra violet radiation by the atmosphere

3. Absorption and re-emission of visible light by the atmosphere

4. Absorption and re-emission of visible light by clouds

Ans- Absorption and re-emission of infrared radiation by the atmosphere

Explanation- The greenhouse effect describes the increase in global temperature as a result of greenhouse gases. Carbon dioxide, methane, and nitrous oxides are examples of greenhouse gases. The longer wavelengths of outgoing infrared light from Earth's surface are absorbed by greenhouse gases in the atmosphere. The infrared radiation is then emitted in all directions, both upward and downward.

3. The result of acid disposition is:

1. Dying forests and lakes

2. Acid indigestion in humans

3. Greenhouse effect lessens 

4. All of these

Ans- Dying forests and lakes

Explanation- Acid rain causes deposition of acidic components into the soil which in turn results in lowered fertility in the soli, which ultimately leads to the depletion of the trees population. With the increased concentration of acidic components, the acidity of water bodies increases making it unsuitable for the survival of aquatic flora and fauna, ultimately leading to population decline.

4. The reason for soil pollution is ________________.

1. Ozone

2. Aerosol

3. PAN

4. Acid rain

Ans- Acid rain

Explanation- Acid rain is among the several reasons for soil pollution as the soil gets polluted with acidic components, it leads to the increasing infertility of the soil. 

These are some common environmental science questions with multiple choices that you can keep in mind while preparing for biology exams.