Human Body Systems
The digestive system breaks food down into nutrients the body can use.
Question: What is the main function of the digestive system?
Answer: To break down food and absorb nutrients.
10 points
A student freezes orange juice into popsicles overnight.
Question: Was this a physical or chemical change?
Answer: It was a physical change because the substance only changed state.
10 points
A hurricane forms over warm ocean water and moves toward the North Carolina coast.
Question: Why does warm ocean water help hurricanes become stronger?
Answer: Warm ocean water provides energy that fuels the storm.
20 points
A student rolls two soccer balls across the gym floor. One ball is kicked softly and the other is kicked hard. The harder-kicked ball moves faster and travels farther.
Question: Why did the second ball travel farther?
Answer: The second ball had more force applied to it, causing it to move faster and farther.
10 points
Algae in a pond use sunlight to make their own food.
Question: What type of organism is algae?
Answer: A producer.
5 points
The lungs take in oxygen while the heart pumps blood carrying oxygen to body cells.
Question: Which two systems are working together?
Answer: The respiratory system and circulatory system.
10 points
A student mixes salt into warm water until the salt can no longer be seen. Later, the water evaporates and the salt remains behind.
Question: What does this show about the salt and water mixture?
Answer: No new substance formed because the salt could still be separated from the water.
10 points
Meteorologists predict thunderstorms after studying rising temperatures, humid air, and incoming cold fronts.
Question: What type of data are meteorologists using to make predictions?
Answer: Weather data.
20 points
A heavy wagon and a light wagon are pushed with the same amount of force. The lighter wagon speeds up much quicker.
Question: Why did the lighter wagon accelerate more quickly?
Answer: The lighter wagon had less mass, so less force was needed to change its motion.
10 points
Grasslands support large populations of grazing animals because grasses grow quickly and spread across wide areas.
Question: Why are producers important in ecosystems like grasslands?
Answer: Producers provide the main source of energy for the ecosystem.
10 points
Muscles in the arms contract and relax to lift a heavy backpack.
Question: Which system helps the muscles pull against the bones?
Answer: The skeletal system.
5 points
When milk spoils, it develops a sour smell and cannot return to its original form.
Question: Why is this considered a chemical change?
Answer: New substances formed during the spoiling process.
10 points
A town near the ocean usually experiences cooler summers and warmer winters than inland towns.
Question: Why does the ocean affect the town’s climate this way?
Answer: Water heats and cools more slowly than land, helping moderate temperatures.
25 points
A student notices that a sled slides easily across ice but slows down quickly on grass.
Question: What explains the difference in motion?
Answer: Grass creates more friction than ice, causing the sled to slow down faster.
15 points
A hawk eats snakes, and snakes eat mice in a forest ecosystem.
Question: If the mouse population decreases greatly, what will most likely happen to the snake population?
Answer: The snake population will likely decrease because there is less food available.
10 points
The brain sends signals through nerves to help a person catch a falling glass before it hits the floor.
Question: Which body system controls these quick responses?
Answer: The nervous system.
5 points
Steel bridges are built with joints that allow the metal to move slightly during hot weather.
Question: Why is this necessary?
Answer: Metal expands when heated and contracts when cooled.
15 points
Water from lakes, rivers, and oceans changes into water vapor because of the Sun’s heat.
Question: Which stage of the water cycle is occurring?
Answer: Evaporation.
5 points
A runner travels 100 meters east in 25 seconds during a race.
Question: What was the runner’s speed?
Answer: The runner’s speed was 4 meters per second.
5 points
A lake ecosystem contains fish, insects, frogs, algae, and aquatic plants. Pollution kills much of the algae population.
Question: Why could this harm many other organisms in the ecosystem?
Answer: Algae are producers and provide energy for many organisms in the food web.
15 points
A microscope shows tiny muscle cells grouped together to form muscle tissue, which forms the heart.
Question: According to levels of organization, what structure is formed when tissues work together?
Answer: An organ.
10 points
A student tears a sheet of paper into tiny pieces.
Question: Did the amount of matter change? How do you know?
Answer: No, the amount of matter stayed the same. Mass cannot be created or destroyed.
15 points
After a thunderstorm, rainwater soaks into the soil, flows into streams, and eventually reaches the ocean.
Question: What part of the water cycle includes water moving across Earth’s surface?
Answer: Runoff.
5 points
A parachute slows a skydiver as they fall toward Earth.
Question: What force from the air helps reduce the skydiver’s speed?
Answer: Air resistance, a type of friction, slows the skydiver.
10 points
Earthworms break down dead leaves in the soil and return nutrients to the ground.
Question: What important role do earthworms play in ecosystems? Explain using details.
Answer: They act as decomposers by breaking down dead matter into usable nutrients for plants.
15 points