APES Ecosystem Unit Review

Front

What is directional selection?

Back

Directional selection is a mode of natural selection in which a single phenotype is favored, causing the allele frequency to shift in one direction.

Front

Why do terrestrial trophic pyramids usually not have levels higher than tertiary consumers?

Back

A large proportion of energy is lost as heat as it is transferred up the pyramid, so there is not enough energy available to support another level.

Front

According to the theory of island biogeography, why would an island 5 kilometers from a continent have more species than one 15 kilometers away?

Back

There are more species that have the ability to travel 5 kilometers than can travel 15 kilometers.

Front

What historical pesticide caused problems for birds by making their eggs too thin?

Back

DDT (Dichloro-Diphenyl-Trichloroethane) caused problems for birds because it made their eggs too thin.

Front

What is biomagnification?

Back

Biomagnification is the process by which the concentration of toxic substances increases in organisms at each successive level of the food chain.

Front

Define trophic levels in an ecosystem.

Back

Trophic levels are the hierarchical levels in an ecosystem, comprising producers, primary consumers, secondary consumers, and tertiary consumers.

Front

What is the role of producers in an ecosystem?

Back

Producers, such as plants and phytoplankton, convert solar energy into chemical energy through photosynthesis, forming the base of the food chain.

Front

Explain the concept of energy transfer in a food chain.

Back

Energy transfer in a food chain is inefficient, with approximately 90% of energy lost at each trophic level due to metabolic processes, heat, and waste.

Front

What is the significance of keystone species in an ecosystem?

Back

Keystone species are crucial for maintaining the structure of an ecosystem; their removal can lead to significant changes and loss of biodiversity.

Front

Describe the concept of ecological succession.

Back

Ecological succession is the process by which ecosystems change and develop over time, often following a disturbance, leading to a more stable community.