ECOLOGY

What is the ecological term for a group of different types of organisms that live together and interact with each other?

• Community

• Domain

• Ecosystem

• Population

In the diagram, which of the processes labelled A to D transfers the largest mass of carbon per year in a woodland ecosystem?

• A

• B

• C

• D

What material is formed when organic matter is not fully decomposed in acidic waterlogged soils?

• Coal

• Hydrogen

• Oil

• Peat

Hummingbirds eat flower nectar and small insects. To which nutritional group do they belong?

• Autotrophs

• Consumers

• Detritivores

• Saprotrophs

Which organism can best be described as a saprotroph?

• A fungus that digests its food externally and absorbs the products of digestion

• A beetle that feeds by ingesting the dung of other animal species and digesting its food internally

• A single-celled eukaryote that is able to photosynthesize and consumes smaller organisms by endocytosis

• A giraffe that feeds by ingesting leaves from an acacia tree

The diagram shows the food web for an aquatic ecosystem in which letters R–Z represent individual species. Which organism is a tertiary consumer?

• Organism T

• Organism U

• Organism W

• Organism Y

Which organisms produce methane in anaerobic environments such as waterlogged soils?

• Archaea

• Fungi

• Eukaryotes

• Eubacteria

In an ecosystem, in the transfer of carbon from producers to consumers, what is carbon transferred as?

I. Carbon dioxide

II. Protein

III. Hydrogencarbonate ions

• I only

• II only

• I and II only

• I and III only

The Silver Springs feed into the Silver River in Florida. The diagram shows a pyramid of energy for the Silver Springs ecosystem. The units are kJ m^–2 y^–1. What do level I and level III represent in the pyramid of energy?

• l sunlight, lll secondary consumer

• l producer, lll tertiary consumer

• l producer, lll secondary consumer

• l primary consumer, lll tertiary consumer

Which is not essential in a viable mesocosm?

• Light source

• Autotroph

• Saprotroph

• Herbivore