Human Impact on the Environment — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. A factory dumps warm water into a river daily. Which chain of effects is MOST likely?
A) River cools, oxygen rises, more fish thrive
B) Water warms, oxygen drops, fish struggle to survive
C) Plants grow faster only, no animal effect
D) Water freezes earlier each winter
Thermal pollution lowers oxygen and stresses fish and other aquatic life.
2. Read: 'A neighborhood plants 200 trees along streets and parks.' Which long-term result is MOST likely?
A) Less shade and hotter sidewalks
B) Cleaner air, cooler streets, and more bird habitats
C) Fewer insects and birds in the area
D) Higher carbon dioxide near the trees
Urban trees cool cities, clean air, and support wildlife communities.
3. A community can only fund ONE plan. Which gives the BIGGEST environmental benefit?
A) Buy disposable cups for the town hall
B) Pave a new parking lot in the park
C) Add solar panels and recycling bins to the school
D) Replace bikes with extra cars for staff
Solar power and recycling reduce pollution and waste at the same time.
4. After a city bans single-use plastic bags, which outcome is MOST expected over years?
A) More plastic in oceans
B) Less plastic litter and lower waste in waterways
C) More turtles eating plastic bags
D) Higher landfill volume from bags
Fewer plastic bags means less litter and safer rivers and oceans.
Part B: Fill in the Blank
Write the correct answer on each line.
1. When a species disappears forever from Earth, it becomes extinct.
Extinction is permanent and removes an animal from every ecosystem.
2. An area set aside to protect wildlife is called a nature reserve.
Nature reserves give habitats lasting protection from human harm.
3. Farming methods that protect soil and water are called sustainable agriculture.
Sustainable farming meets needs today without ruining future land.
4. A scientist who studies how living things interact with the environment is an ecologist.
Ecologists study ecosystems to help solve human impact problems.
5. Working as a community to clean a park is called a service project.
Service projects let neighbors share the work of protecting nature.