CP Environmental Science Name: _________________________________________ Unit 2B Homework- Biodiversity Paper Edition 1. Why is genetic diversity important for the survival of a species? -Genetic diversity refers to all the different genes contained within all members of a population. Genetic diversity plays an important role in the survival and adaptation of a species. When a population’s habitat changes, the population may have to adopt to survive; the ability of the population to adapt to the changing environment will determine their ability to cope with an environmental challenges. 2. Describe three levels of biodiversity. Which is most commonly meant by biodiversity? - Species Diversity – refers to the number of different species in an area (received the most attention- most commonly meant by biodiversity) Ecosystem Diversity – refers to the variety of habitats, communities, and ecological processes within and between ecosystems. Genetic Diversity - refers to all the different genes contained within all members of a population. 3. Explain how biodiversity is important to ecosystems, and give examples of how it is important to humans. Biodiversity is important to each ecosystem because every species plays an important role in an ecosystem. Every species is dependent on or depended upon by at least one other species in order to survive. Biodiversity is important to humans because people use variety of organisms on Earth for food, clothing, shelter, and medicine. People also use different plant species to produce medicine. People also value biodiversity for aesthetic or personal enjoinment- camping, keeping pets, watching wildlife, national parks and many more aesthetical benefits. 4. Why do scientists warn that a mass extinction is occurring now? - Scientists are warning of mass extinction because the rate of extinction is estimated to have increased by a multiple of 50 since 1800. They state that by the end of 2100, up to 25% of all species on Earth may have become extinct. CP Environmental Science Name: _________________________________________ 5. Describe four ways that species are being threatened with extinction globally. 1. Habitat Destruction and Fragmentation – In the process of building homes and harvest resources, humans destroy and fragment the habitats of other species. 75% of all extinction is caused by habitat destruction. 2. Invasive Exotic Species – Humans brought many exotic species that do not belong to a certain ecosystem. Since the exotic species are introduced to a predator-free new environment, they can become an invasive species and can threaten the native species. 3. Harvesting, Hunting, and Poaching – Excessive harvesting and poaching can also lead to extinction. Many countries around the world have laws to regulate hunting, fishing, harvesting and trade of wildlife. However, in poor countries, an illegal activity such as poaching occurs where local species are used as source of food, medicine, or income. 4. Pollution - Pesticides, cleaning agents, drugs, and other chemicals used by humans are making their way into food webs around the globe. 6. Define and give examples of endangered species and threatened species. Endangered- An endangered species is a species that is likely to become extinct if protective measures are not taken immediately. (ex: Amur Tiger – endangered due to hunting, now protected by law) Threatened- Threatened species is a species that has a declining population and that is likely to become endangered if it is not protected. (ex: Polar Beardue to ongoing and potential loss of their sea ice habitat resulting from climate change, Polar Bears were listed as threatened species in 2008). 7. List areas of the Earth that have high levels of biodiversity and many threats to species. - Tropical Rain Forests – ( today, it covers around 7% of the Earth’s land surface) - Coral Reefs and Coastal Ecosystems – It occupies a small fraction of the marine ecosystem yet contains the majority of the biodiversity. The coral reefs provide the people with food and tourist revenue. But nearly 60% of the coral reefs on our planet are threatened by human activities such as overfishing and pollution. - Islands – When an island is formed, it is colonized by a limited number of species. Some of the species may evolve into several new species. However, due to human CP Environmental Science Name: _________________________________________ activities and transportation of exotic species, the island species are endangered by competition from exotic species. 8. Describe one way in which the IUCN helps to protect species and habitats. The International Union for the Conservation of Nature and Natural Resources (IUCN) had published a “Red Lists” of species in danger of extinction around the world. The IUCN also advises governments on ways to manage their natural resources and also they support conservation projects. 9. Describe four types of efforts to save individual species. 1. Captive-Breeding Programs – Restoring a population of a species through breeding species in captivity, with hope to reintroducing populations to their natural habitats (ex: the California Condor). 2. Preserving Genetic Material – Saving genetic material (germ-plasm banks) of plants and animals for future use in research or species-recovery efforts. 3. Zoos, Aquariums, Parks, and Gardens – Today, zoos house the few remaining members 4. Habitat conservation plan – a plan that attempts to protect one or more species across large areas of land through trade-offs or cooperative agreements. 10. Explain the advantages of protecting entire ecosystems rather than individual species. - The advantage of protecting entire ecosystems is the most effective way to save species because species confined to a small area could be wiped out by a single natural disaster. Some species require a large range to find adequate food or mate. Therefore, protecting the habitats of endangered and threatened species often means preserving or managing large areas (entire ecosystem). 11. Describe the main provisions of the Endangered Species Act (ESA). - The U.S. Fish and Wildlife Services (USFWS), must compile a list of all endangered and threatened species. Endangered and threatened animal species may not be caught or killed. Endangered or threatened plants on federal land may not be uprooted, sold or traded. CP Environmental Science - Name: _________________________________________ The federal government may not carry out any project that jeopardizes endangered species. The USFWS must prepare a species recovery plan for each endangered and threatened species. 12. Some species are so important to the functioning of an ecosystem that they are called a. Threatened species. b. Keystone species. c. Endangered species. d. Extinct species. 13. Which of the following statements about the Endangered Species Act is not true? a. Parts of an endangered animal, such as feathers or fur, may be traded or sold but only if the animal is not killed. b. A species is considered endangered if it is expected to become extinct in the near future. c. The federal government cannot carry out a project that may jeopardize an endangered plant. d. A recovery plan is prepared for all animals that are listed as endangered. 14. What are invasive species, and how do they endanger other species? An invasive species is a species that is not native to a particular region or ecosystem. When a species is introduced to a new environment, it can become invasive due to the fact that it does not have a natural predator to control their population. When the species becomes invasive, it overtakes the new territory and it threatens native species by tacking their food resources or by killing them. 15. Math Practice: There are 297,326 identified plant species on Earth today. Scientists estimate that this number makes up 84% of the total plant species on the Earth. Estimate how many plant species are actually in existence today, both identified and unknown. Show your work. 0.84(x) = 297,326 species solve for x x = 297,326 / 0.84 = 353,960 species total, known and unknown