Activities Key Terms Quizzes Art Chapter 4 Self-Quiz
Unit 1: Diversity of Life Biodiversity Review
  1. An is all of the species that live in a given area and the areas or they inhabit. refers to the number of species in the entire world or more locally, a particular ecosystem. There are about 3 million to 30 million species on Earth; of these only million have been discovered and named. Loss of biodiversity is reflected in the loss of species, or .
  2. The most diverse ecosystem is the . These rainforests are losing about 27,000 species per year. Why is preserving biodiversity important?
  3. At least 5 episodes have been documented in the past, the most severe was 250 million years ago in the late Period. Previous extinctions were the result of climate , increased , changing , impact, or moving continents.
  4. Humans may have been responsible for species extinctions in the past. The disappearance of large animals from continents and islands such as , , , and coincided with the arrival of humans. Humans may be the main agent for a mass extinction.
  5. The biggest threat to biodiversity is loss and deterioration. Habitat can reduce breeding territories for area-sensitive species such as the Greater Sage-Grouse and songbirds due to the effect. Human population growth is a main factor in habitat loss.
  6. The introduction of species can displace native species which are not to the alien species. Sometimes an exotic species is introduced as a of other invasives, but this has its own pitfalls!
  7. Other threats to biodiversity include change, pollution, over- and over- . Human activity is a major component in these factors as well.
  8. The more species that are present in an ecosystem, the more that ecosystem is, because more can be used. The hypothesis predicts a sudden collapse of an ecosystem when species loss reaches a threshold due to the among species. The more diverse an ecosystem, the more resilient it is to environmental challenges. What is the value of biodiversity?
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