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Chapter 6 Review Changes in Ecosystems 5th Grade inherit- receiving of parents genes; offspring receive half from the mother and half from the father mutation- a change in an organisms genes structural adaptation- a body part that helps an organism survive in its ecosystem; ex. A frog’s long, sticky tongue for catching insects behavioral adaptation- inherited behaviors that help organisms survive; ex. A duck flying south for the winter pesticide- poisons that kill insects; ex. DDT extinct- has no members of its kind of species left alive on earth; ex. Tasmanian wolf endangered- the population of the organism is so low that it is in danger of becoming extinct; ex. The gray bat 1. Explain what DNA is. It contains all the information needed for making an organism; found in all the nucleuses of cells 2. How do earthworms affect the environment as they move through soil? They enrich the soil with the waste that they give off from their digested material and the holes that they make bring oxygen to the roots of plants 3. When parents pass on genes what percent comes from the mother and what percent comes from the father? 50% from the mother and 50% from the father 4. Name 4 structural adaptations of a frog and explain how they help the frog survive. The sticky pads on a tree frog help it to climb; Their green skin help the blend in and avoid predators (camouflage); eyes on the top so when it goes under water it can still see predators and prey; strong legs and webbed feet help it swim 5. Name two behavioral adaptations of a duck and how they help it to survive. Flying south for the winter to find food; It’s quack will warn its babies or others about predators 6. How can new species be introduced into an environment? They can stow away like rats on a ship; be brought by humans 7. Describe the situation with the zebra mussel. They were brought in by ships by accident, they have no natural predators here so their population exploded, they stop up pipes and take the food of other natural mussel species 8. What is a learned behavior and give an example of one? A behavior that they learn from their parent; a cub learns to hunt from its mother 9. Explain what a mutation is. A change in a gene 10. Can a mutation be helpful, harmful, or both? It can be helpful or harmful 11. Why does acid rain form and what does it hurt? It forms from air pollution and it hurts the whole ecosystem where it falls (plants, lakes, streams, and the organisms) 12. If a lake becomes polluted with acid rain, what can be done to help the situation? Lime can be added to change the pH but it takes a while for the lake to return to normal 13. Explain what DDT is and how it ended up causing the bald eagle to become an endangered species? DDT is a pesticide that when spread on crops ended up in streams that eagles caught their fish from. After eating the fish with DDT in their system they laid eggs with thin shells. These eggs did not hatch and the eagle population reached the endangered level until DDT was banned. 14. Why did the dodo become extinct? It’s a flightless bird that survived well on an island until sailors arrived and brought rats, pigs, and monkeys into the ecosystem. The birds could no longer defend themselves or fly to safety on other islands. 15. How do pesticides and antibiotics cause insects and bacteria to become resistant to their chemicals? They develop adaptations to living around antibiotics and pesticides. When they do they pass these traits on to their offspring. And the diseases the bacteria cause become harder to treat and the insects cannot be killed. 16. Tell what a variable is in an experiment. Variables are the things that can be changed in the experiment.