Option G Katie Morris G 3.3 Discuss reasons for the conservation of biodiversity using rainforests as an example. • Rainforests are area in the world with highest biodiversity • Ethical- all plants/animals have a right to live. Future humans have a right to see the world that we see. • Ecological- animals depend on other animals. Species have already adapted • Aesthetic- rainforests are beautiful • Economic- Many resources lie in rainforests (medicine) G 3.4 List three examples of the introduction of alien species that have had significant impacts on ecosystems. • Purple loosestrife- overtook other native plants and had no predators. • Brown tree snake- extirpated bird species and bats by preying on them. • Ophiostoma ulmi- caused disease in trees that killed many native trees G 3.5 Discuss the impacts of alien species on ecosystems. • Alien species can outcompete other native species for limited resources like food and land. • Can eat organisms and create a destroyed food chain that must then adapt or become extinct. • Can interbreed and cause extinction of a species or create new species. • Can keep other invader species under control. G 3.6 Outline one example of biological control of invasive species. • Control pest species • Prickly pear cactus invaded Australia, but has been controlled by South American moth • Moth eats cactus G 3.7 Define biomagnification • Process in which chemical substances become more concentrated at each trophic level. G 3.8 Explain the cause and consequences of biomagnification, using a named example. • Animals at higher trophic levels need to eat more organisms at lower levels in order to get enough energy because 90% of the energy is lost at each level. • If a lower level species has poison in it, like the mosquitos that were infected with DDT, the larger animals, like geckos, that eat many of them, are ingesting large amounts of poison that could kill them. G 3.9 Outline the effects of ultraviolet radiation on living tissues and biological productivity. • UV radiation causes DNA damage, like mutations that cause protein malfunction. Or cancer. • Can also damage organic molecules, hurting enzymes, nitrogen-fixing bacteria in soil • Causes eye damage (cataracts) • Lower immune system • Food shortage G 3.10 Outline the effect of chlorofluorocarbons (CFCs) on the ozone layer. • CFCs speed depletion of ozone layer. G. 3.11 State that ozone in the stratosphere absorbs UV radiation. • There is a limit to UV absorption in the atmosphere. Therefore the stratosphere absorbs UV radiation. G 4.5 Discuss the advantages of in situ conservation of endangered species. • Conserve natural habitat • Ideal for threatened species • Long term sustainability G 4.6 Outline the use of ex situ conservation measures, including captive breeding of animals, botanic gardens and seed banks. • Replanting plants in areas they know will survive, like botanic gardens. • Captive breeding ensures that animals will breed and increase population size. • Seed banks allow seeds to spread easily in order to fertilize. G 5.4 Describe the methods used to estimate the size of commercial fish in stocks. • Tag and release • Perception made by fisherman • Record number and type of fish and throw back • Study catches made G 5.5 Outline the concept of maximum sustainable yield in the conservation of fish stocks. • The fish population increases as fishermen fish for the fish. • Only until a point. Then the fish population starts to decrease as they are over fished. – Fish populations are very difficult to find and therefore, people often disagree when it comes to fishing in order to conserve fish.