Energy in Ecosystems — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. Which human action removes homes for many Grade 5 ecosystem animals?
A) Clearing forests for farms and cities
B) Planting more native trees
C) Setting up wildlife reserves
D) Cleaning trash from rivers
Cutting forests destroys habitat, breaking food-web links and lowering biodiversity in Grade 5 science.
2. What is an invasive species?
A) A non-native species that harms local food webs
B) Any animal born in a forest
C) A plant that only grows in deserts
D) A predator that lives in zoos
Invasive species are introduced animals or plants that outcompete native species in food webs.
3. How does water pollution affect a pond food web?
A) It can poison producers and harm consumers up the chain
B) It always makes more fish appear
C) It turns ponds into deserts overnight
D) It only affects birds in the sky
Polluted water hurts plants and small animals, and the harm passes up to predators in the Grade 5 food web.
4. Which action best protects food-web biodiversity?
A) Creating protected parks and wildlife reserves
B) Filling wetlands with concrete
C) Releasing pet snakes into local forests
D) Dumping factory waste into streams
Protected areas keep habitats whole, supporting healthy food webs and biodiversity in Grade 5 ecosystems.
Part B: Fill in the Blank
Write the correct answer on each line.
1. When people cut forests for cities, this is called habitat destruction.
Habitat destruction breaks food-web links and reduces biodiversity in Grade 5 ecosystems.
2. Chemicals from factories that harm rivers are a form of pollution.
Pollution damages producers and consumers, weakening the entire Grade 5 food web.
3. A non-native species that harms local food webs is called invasive.
Invasive species outcompete native species and disrupt food-web balance in Grade 5 science.
4. The variety of species in an ecosystem is called biodiversity.
Biodiversity supports stable food webs and helps ecosystems handle change in Grade 5 science.
5. When food webs lose species and stop balancing, they fall out of equilibrium.
Loss of equilibrium means populations swing wildly, harming the whole ecosystem in Grade 5 science.