Energy enters an ecosystem by being used to convert low-energy carbon dioxide into high-energy carbohydrate, then passes through one or more of the organisms of the community, and is then lost to the ecosystem. Eventually, all of the energy that enters the ecosystem is lost in the form of heat.

Correct Option: B

Energy enters an ecosystem by being used to convert low-energy carbon dioxide into high-energy carbohydrate, then passes through one or more of the organisms of the community, and is then lost to the ecosystem. Eventually, all of the energy that enters the ecosystem is lost in the form of heat.

Ecosystems contain essentially two kinds of commodities: matter (nutrients) and energy. Material nutrients cycle through the biotic and abiotic parts of the ecosystem, available for repeated use by the organisms in the ecosystem's community. However, energy enters an ecosystem by being used to convert low-energy carbon dioxide into high-energy carbohydrate, then passes through one or more of the organisms of the community, and is then lost to the ecosystem. Eventually, all of the energy that enters the ecosystem is lost in the form of heat.

Correct Option: B

Ecosystems contain essentially two kinds of commodities: matter (nutrients) and energy. Material nutrients cycle through the biotic and abiotic parts of the ecosystem, available for repeated use by the organisms in the ecosystem's community. However, energy enters an ecosystem by being used to convert low-energy carbon dioxide into high-energy carbohydrate, then passes through one or more of the organisms of the community, and is then lost to the ecosystem. Eventually, all of the energy that enters the ecosystem is lost in the form of heat.

Ecological balance is a state of dynamic equilibrium within a community of organisms in which genetic, species and ecosystem diversity remain relatively stable, subject to gradual changes through natural succession." In other words, it refers to stable balance in the numbers of each species in an ecosystem. So to maintain this balance, the delicate balance between the organisms constituting and ecosystem should be understood.

Correct Option: D

Ecological balance is a state of dynamic equilibrium within a community of organisms in which genetic, species and ecosystem diversity remain relatively stable, subject to gradual changes through natural succession." In other words, it refers to stable balance in the numbers of each species in an ecosystem. So to maintain this balance, the delicate balance between the organisms constituting and ecosystem should be understood.

Projections of future climate change suggest further global warming, sea level rise, and an increase in the frequency and severity of some extreme weather events. Over the next several millennia, even if emissions were drastically reduced, global temperatures would remain close to their highest level for at least 1,000 years. The coast will suffer severe impacts from sea level rise.

Correct Option: D

Projections of future climate change suggest further global warming, sea level rise, and an increase in the frequency and severity of some extreme weather events. Over the next several millennia, even if emissions were drastically reduced, global temperatures would remain close to their highest level for at least 1,000 years. The coast will suffer severe impacts from sea level rise.

A Natural region is a basic geographic unit. Usually it is a region which is distinguished by its common natural features of geography, geology and climate. The surface of the Earth is divided into twelve natural regions. These regions have been categorized on the basis of surface features, climate and vegetation.

Correct Option: A

A Natural region is a basic geographic unit. Usually it is a region which is distinguished by its common natural features of geography, geology and climate. The surface of the Earth is divided into twelve natural regions. These regions have been categorized on the basis of surface features, climate and vegetation.