Environment & Ecology MCQ Questions 2026 – Topic-wise Practice for UPSC, SSC, Forest Services

Which of the following gases is a major contributor to the greenhouse effect?

Carbon dioxide

Methane

Nitrous oxide

All of the above

Medium

💡 Explanation

All three gases, carbon dioxide, methane, and nitrous oxide, are potent greenhouse gases that contribute to global warming and climate change.

Which of the following species is an endangered species in India?

Bengal tiger

Asiatic lion

Indian rhinoceros

All of the above

Medium

💡 Explanation

The Bengal tiger, Asiatic lion, and Indian rhinoceros are all endangered species in India, with declining populations due to habitat loss and human-wildlife conflict.

Which of the following types of ecosystems is characterized by a diverse array of plant and animal species?

Tropical rainforest

Desert ecosystem

Grassland ecosystem

Temperate deciduous forest

Medium

💡 Explanation

Tropical rainforests are among the most biodiverse ecosystems on the planet, with a vast array of plant and animal species, including many that are found nowhere else on Earth.

Which of the following pollutants is a major contributor to acid rain?

Sulfur dioxide

Nitrogen oxides

Carbon monoxide

Particulate matter

Medium

💡 Explanation

Sulfur dioxide and nitrogen oxides are the primary pollutants responsible for acid rain, which can have devastating effects on ecosystems and human health.

Which of the following types of waste is a major contributor to pollution in India?

Industrial waste

Domestic waste

Agricultural waste

All of the above

Medium

💡 Explanation

Industrial waste, domestic waste, and agricultural waste all contribute to pollution in India, with significant impacts on human health and the environment.

Which of the following species is an example of a keystone species in a given ecosystem?

Lion

Elephant

Giraffe

Tiger

Medium

💡 Explanation

Lions are often considered keystone species in their ecosystems, playing a crucial role in maintaining the balance of their environments.

Which of the following types of pollution is caused by the release of chemicals into the environment?

Air pollution

Water pollution

Soil pollution

Chemical pollution

Medium

💡 Explanation

Chemical pollution refers to the release of chemicals into the environment, which can have devastating effects on ecosystems and human health.

Which of the following species is an example of a migratory species in India?

Bengal tiger

Asiatic lion

Indian rhinoceros

Bar-headed goose

Medium

💡 Explanation

The bar-headed goose is a migratory species in India, with populations that migrate between summer and winter habitats in the Himalayas.

Which of the following types of waste is a major contributor to pollution in urban areas?

Industrial waste

Domestic waste

Agricultural waste

Construction waste

Medium

💡 Explanation

Domestic waste is a major contributor to pollution in urban areas, with significant impacts on human health and the environment.

Which of the following species is an example of a threatened species in India?

Bengal tiger

Asiatic lion

Indian rhinoceros

All of the above

Medium

💡 Explanation

The Bengal tiger, Asiatic lion, and Indian rhinoceros are all threatened species in India, with declining populations due to habitat loss and human-wildlife conflict.

Which of the following types of ecosystems is characterized by a lack of vegetation?

Flooded ecosystem

Desert ecosystem

Grassland ecosystem

Temperate deciduous forest

Medium

💡 Explanation

Desert ecosystems are characterized by a lack of vegetation, with limited plant growth due to extreme temperatures and low rainfall.

Which of the following pollutants is a major contributor to air pollution in India?

Sulfur dioxide

Nitrogen oxides

Carbon monoxide

Particulate matter

Medium

💡 Explanation

Particulate matter is a major contributor to air pollution in India, with significant impacts on human health and the environment.

Which of the following species is an example of a threatened species in the Himalayas?

Snow leopard

Red panda

Asiatic black bear

All of the above

Medium

💡 Explanation

The snow leopard, red panda, and Asiatic black bear are all threatened species in the Himalayas, with declining populations due to habitat loss and human-wildlife conflict.

Which of the following types of ecosystems is characterized by a high level of human impact?

Tropical rainforest

Desert ecosystem

Grassland ecosystem

Urban ecosystem

Medium

💡 Explanation

Urban ecosystems are characterized by a high level of human impact, with significant impacts on the environment and human health.

Which of the following pollutants is a major contributor to water pollution in India?

Sulfur dioxide

Nitrogen oxides

Carbon monoxide

Industrial chemicals

Medium

💡 Explanation

Industrial chemicals are a major contributor to water pollution in India, with significant impacts on human health and the environment.

Which of the following types of ecosystems is characterized by a high level of species diversity?

Tropical rainforest

Desert ecosystem

Grassland ecosystem

Temperate deciduous forest

Medium

💡 Explanation

Tropical rainforests are characterized by a high level of species diversity, with a vast array of plant and animal species, including many that are found nowhere else on Earth.