Habitats and Ecosystems — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. Why do arctic foxes turn white in winter?
A) To attract mates in the snow.
B) To blend in with snow and hide from predators.
C) To reflect heat and stay warm.
D) To scare away polar bears.
An arctic fox's white winter coat matches the snow, which makes it much harder for predators to spot. This kind of camouflage is an adaptation that helps the fox stay safe.
2. Which food chain is in the correct order?
A) hawk → mouse → grass → sun
B) sun → grass → mouse → hawk
C) mouse → sun → hawk → grass
D) grass → sun → mouse → hawk
Energy in a food chain flows from the sun to a producer and then up to consumers. Sunlight feeds the grass, the grass feeds the mouse, and the mouse feeds the hawk, so the order goes sun, grass, mouse, hawk.
3. A bear eats berries, fish, and honey. What type of consumer is it?
A) herbivore
B) carnivore
C) omnivore
D) decomposer
Berries and honey come from plants, while fish are animals. An animal that eats both plant foods and animal foods is called an omnivore.
4. What would happen to hawks if the mouse population suddenly dropped?
A) Hawks would have more food.
B) Hawks would have less food and their numbers could drop.
C) Hawks would move to the ocean.
D) Nothing would change for hawks.
Hawks rely on small animals like mice for energy. If mice suddenly became scarce, the hawks would struggle to find enough food, and over time fewer hawks would be able to survive and raise young.
Part B: Fill in the Blank
Write the correct answer on each line.
1. The place where a specific animal lives within a habitat is its niche.
Within a habitat, each animal has its own role and the exact spot where it lives, hunts, or hides. That special place and job is called a niche.
2. Camels have long eyelashes to keep sand out of their eyes.
Desert winds blow sand around, which can scratch eyes. Camels grew long eyelashes that act like a screen to keep blowing sand from getting into their eyes.
3. In a pond ecosystem, tadpoles are consumers that eat tiny water plants.
Tadpoles cannot make their own food. Because they eat tiny water plants in the pond, they take in energy from other living things, which makes them consumers.
4. A food web shows many connected food chains in an ecosystem.
Real ecosystems usually have many animals that eat several different foods, so their food chains cross and overlap. When you draw all those connections together, the picture looks like a web.
5. Polar bears have black skin under white fur to absorb heat.
Polar bears actually have black skin under their thick white fur. The dark skin soaks up sunlight and helps the bear hold on to heat in the freezing Arctic.