Understanding Biodiversity and Ecosystems

What does the term "biodiversity" refer to?

• The diversity of climates on Earth

• The diversity of genes, species, and habitats on Earth

• The diversity of human cultures

• The diversity of languages spoken

What is the primary source of all biodiversity?

• Phenotypic diversity

• Genetic diversity

• Species diversity

• Habitat diversity

Which process is responsible for the divergence of genotypes and phenotypes?

• Photosynthesis

• Natural selection

• Respiration

• Decomposition

What is the estimated number of "known" species on Earth today?

• 500,000

• 1.8 million

• 10 million

• 100 million

What is the term for the process of becoming most fit for a particular environment?

• Extinction

• Adaptation

• Mutation

• Migration

Which of the following is a nonadaptive process of evolution?

• Natural selection

• Gene flow

• Photosynthesis

• Respiration

What is the main cause of the current extinction rate?

• Natural disasters

• Habitat loss

• Overpopulation of species

• Increased rainfall

Which of the following is NOT a way humans threaten biodiversity?

• Hunting

• Introducing exotic species

• Planting trees

• Polluting the environment

What is a biological community?

• A group of similar ecosystems

• An assemblage of all populations in a particular area or habitat

• A single species living in an area

• A collection of nonliving components

What is a keystone species?

• A species that is the most abundant in a community

• A species whose loss can lead to the damage or extinction of the entire community

• A species that is the least important in a community

• A species that is always a predator