Environmental Science Quiz

What is the basic unit of ecology?

• Biome

• Ecosystem

• Organism

• Individual

Answer explanation

The basic unit of ecology is the organism, as it represents a single living entity. Organisms interact with each other and their environment, forming the foundation for larger ecological structures like populations and ecosystems.

Which of the following is a biotic component of an ecosystem?

• Sunlight

• Water

• Bacteria

• Soil

Answer explanation

Bacteria are living organisms and thus a biotic component of an ecosystem. In contrast, sunlight, water, and soil are abiotic factors, as they are non-living elements that support life.

The process by which organisms change over time is known as:

• Evolution

• Succession

• Adaptation

• Symbiosis

Answer explanation

The process by which organisms change over time is called evolution. It encompasses the gradual changes in species through natural selection and genetic variation, distinguishing it from terms like succession, adaptation, and symbiosis.

A food chain represents the flow of energy from:

• Producer to consumer to decomposer

• Consumer to producer to decomposer

• Decomposer to consumer to producer

• Producer to decomposer to consumer

Answer explanation

A food chain illustrates how energy flows from producers (like plants) to consumers (like animals) and finally to decomposers (like fungi and bacteria) that break down dead matter, completing the cycle.

The primary producers in an ecosystem are:

• Herbivores

• Carnivores

• Decomposers

• Plants

Answer explanation

Plants are the primary producers in an ecosystem as they convert sunlight into energy through photosynthesis, forming the base of the food chain. Herbivores and carnivores rely on plants for energy, while decomposers break down organic matter.

The symbiotic relationship between a fungus and a plant root is called:

• Parasitism

• Commensalism

• Mutualism

• Predation

Answer explanation

The symbiotic relationship between a fungus and a plant root is called mutualism because both organisms benefit. The fungus helps the plant absorb nutrients, while the plant provides the fungus with carbohydrates.

Which of the following is a terrestrial ecosystem?

• Ocean

• Pond

• Desert

• River

Answer explanation

A terrestrial ecosystem is one that is primarily land-based. Among the options, the desert is a clear example of a terrestrial ecosystem, characterized by dry conditions and specific flora and fauna adapted to such environments.

The process of ecological succession begins with:

• Pioneer species

• Secondary succession

• Climax community

• Primary succession

Answer explanation

The process of ecological succession begins with pioneer species, which are the first organisms to colonize barren environments. They prepare the habitat for other species, leading to a more diverse ecosystem.

The term "niche" refers to:

• The role of an organism in an ecosystem

• The food an organism eats

• The physical space an organism occupies

• The habitat an organism lives in

Answer explanation

The term "niche" specifically refers to the role of an organism in an ecosystem, encompassing how it interacts with other organisms and its environment, rather than just its habitat or food.

Which of the following is a major factor that influences the distribution of organisms on Earth?

• Climate

• Soil

• Topography

• All of the above

Answer explanation

Climate, soil, and topography all significantly affect where organisms can live. Climate determines temperature and precipitation, soil provides nutrients, and topography influences habitat availability, making 'All of the above' the correct choice.