two balls of unequal mass are hung from two springs that are not identical. the springs stretch the same distance as the two systems reach equilibrium. then both springs are compressed and released.

Which of the following must happen in order for productivity to increase? a. production levels remain unchanged while inputs increase. b. production levels rise while inputs decrease. c. production levels fall while inputs increase.

The graph shows the populations of two species over time. which type of symbiotic relationship does the graph represent? a. commensal b. mutualistic c. parasitic d. parent-offspring e. predator-prey

An ecosystem is shown in the illustration. assume that human activities have led to a decrease in the number of eagles. a virus attack on rabbits has led to a decrease in their population in the ecosystem. which two sentences describe likely effects on the ecosystem? 1. there’s an increase in the number of snakes and insects and a decrease in the number of frogs. 2. there’s an increase in the number of snakes and insects, and the storks face increased competition for food. 3. there’s an increase in the number of storks and a decrease in the number of snakes and insects. 4. there’s an increase in the number of frogs and a decrease in the number of storks and insects. 5. there’s a decrease in the number of snakes, insects, and frogs.