CHECK FOR UNDERSTANDING Name: ® THE SIXTH EXTINCTION? Page 8 DIRECTIONS: Fill in the blanks in the following sentences. Use the words in the word bank below. asteroids ballast dinosaurs endangered Endangered Species Act extinct frogs fuel fungal disease golden frog humans Panama pollution Sixth Extinction whooping cranes 1. T he _______________ is one species that has been declared extinct in the wild. 2. A disease that kills frogs has spread across _______________ in recent years. 3. Nearly 40 percent of the world’s frogs and toads are _______________. 4. Scientists have dubbed the recent phenomenon of many species dying out as the _______________. 5. Scientists believe that _______________ are to blame for the recent mass extinction. 6. _______________ disappeared during the last mass extinction. 7. O ne way humans transport species around Earth is in the _______________ of supertankers. 8. S cientists determined that frogs in Central America were being killed off by _______________. 9. The _____________________________ was passed in 1973 to protect organisms at risk of becoming extinct. 10. T here are only 200 _______________ left in the wild. WIND CATCHER, Page 12 DIRECTIONS: Answer the following questions in complete sentences. 1. What are two disadvantages of burning fossil fuels to generate electricity? _ _______________________________________ ______________________________________________________________________________________________________________ 2. What is a renewable resource? ________________________________________________________________________________ ______________________________________________________________________________________________________________ 3. How do wind turbines produce electricity?______________________________________________________________________ ______________________________________________________________________________________________________________ ______________________________________________________________________________________________________________ 5. What is the purpose of the ground station under the floating turbine? _____________________________________________ ______________________________________________________________________________________________________________ Permission granted by Science World to reproduce for classroom use only. ©2015 by Scholastic Inc. T6 l Science World TEACHER’S GUIDE l APRIL 13, 2015 WWW.SCHOLASTIC.COM/SCIENCEWORLD Answers on T8 4. Why is it beneficial for turbines to be located high in the sky? ____________________________________________________ CHECK FOR UNDERSTANDING Name: ® CAN SCIENCE SAVE YOUR ORANGE JUICE? Page 14 DIRECTIONS: Match each item in the left-hand column below with its definition or description in the right-hand column. ______ 1. citrus greening a. a threat to avocado crops in California ______ 2. citrus psyllid b. the process by which scientists insert new genes into an organism ______ 3. phloem c. a disease that causes citrus trees to grow small, bitter fruit ______ 4. tristeza d. a source of genes that help fight bacterial infection and prevent citrus greening ______ 5. graft e. unit of hereditary material ______ 6. genetic engineering f. an insect that feeds on citrus trees, carrying with it the bacteria that cause citrus greening ______ 7. spinach g. a virus that attacks the roots of some types of orange trees ______ 8. gene h. the most common variety of bananas sold in the U.S. ______ 9. Cavendish i. transplant part of a plant onto another plant ______ 10. drought j. the system that transports sugars throughout a plant NAME THAT ELEMENT! Page 20 DIRECTIONS: Correct the following sentences by crossing out incorrect words or numbers and adding correct words or numbers as necessary. 1. C arbon dioxide gives plants their green hue. 2. The mystery element makes it more difficult for lava to flow. 3. When something burns, it reacts with carbon dioxide to create light. Answers on T8 4. Iron is lighter than the mystery element. 5. The mystery element is the most abundant element in seawater. Permission granted by Science World to reproduce for classroom use only. ©2015 by Scholastic Inc. WWW.SCHOLASTIC.COM/SCIENCEWORLD Science World TEACHER’S GUIDE l APRIL 13, 2015 l T7