Grade 9 Science Exam Review - Solutions 2014 | Page 12

10. Predation is the interaction of organisms whereby one organism eats another. 11. Competition is the interaction of organisms where they vie for the same resources. 12. Mutualism is the interaction of organisms whereby both organisms benefit. 13. Parasite is the interaction of organisms whereby only one organisms benefits from the other. 14. A mouse population begins at 500 individuals. During the year, there are 400 births, 50 deaths, 40 join the population and 25 flee to a neighboring population. a) Calculate the population growth. (400 – 50) + (40 - 25) = 365 mice b) Calculate the growth rate. (500 + 365)/500 x 100% = 173% 15. Sketch a typical predator-prey graph below indicating the predator and prey populations over time. 16. Four ways that humans have an impact on sustainable ecosystems are: pollution, habitat loss, overhunting and drainage of wetlands etc 17. a) Biodiversity refers to the number and type of organisms b) Biodiversity is important to sustainability Page 12 of 17