15. What will happen if there are more predators than preys in an ecosystem?
a. The source of foods will increase.
c. The source of foods will remain the same
b. The source of foods will decrease.
d. Other animals will also decrease in numbe
16. Which of the following pairs of organisms has harmful interaction?
a. A snake and a rat
c. A bird's nest and a tree
b. Orchids and trunk of a tree
d. Butterflies and flowers
17. You put twelve small fish in an aquarium which contains three gallons of water. You fed th
of food. After five days, some of the fish died. Why did it happen?
a. The smelly water in the aquarium was not replaced c. There was no enough space
b. The aquarium did not have enough temperature range d. The aquarium was moved
18. Man interferes with the balance of nature when he
a. Pollutes air and water
c. Disposes his garbage properly
b. Practices selective logging
d. Helps control overpopulation by practicing fam
19. Overpopulation affects the balance of nature. Which of the following does not support th
a.lt may result to death of some organisms, c. Overpopulation may result to fight
b.More consumers may upset the balance of nature. d. More people will work and the bal
improved
20. Which of the following can help conserve our ecosystem?
a. Construct buildings near the river banks,
b. Improve the ecosystem by inviting tourist to visit your place.
c. Protect the forests and bodies of water against harmful activities
d. Encourage the political leaders to build farm to market roads to reach all beautiful place​