HUMAN BODY
Which organ pumps blood throughout the body?
Heart
What process allows green plants to make their own food?
Photosynthesis
What star is at the center of our solar system?
Sun
What are the three common states of matter?
Solid, liquid, gas
What instrument is used to measure temperature?
Thermometer
What organ is mainly responsible for breathing?
Lungs
What plant part absorbs water and minerals from the soil?
Roots
What planet is known as the Red Planet?
Mars
What force pulls objects toward Earth?
Gravity
What do we call a testable explanation for an observation?
Hypothesis
What blood vessels carry blood away from the heart?
Arteries
What gas do plants take in during photosynthesis?
Carbon dioxide
What causes day and night on Earth?
Earth's rotation
What form of energy allows us to see objects?
Light energy
What variable is deliberately changed by the scientist in an experiment?
Independent variable
Which organ absorbs most nutrients from digested food?
Small intestine
What relationship occurs when both organisms benefit?
Mutualism
What movement of Earth around the Sun takes about 365¼ days?
Revolution
A moving bicycle suddenly stops when the brakes are applied. What force opposes its motion?
Friction
A student investigates whether different amounts of sunlight affect plant growth. What is the dependent variable?
Plant growth
A person touches a hot object and immediately pulls their hand away. What part of the nervous system coordinates this quick response?
Spinal cord
In a food chain, what would most likely happen to the population of grass if the number of grasshoppers greatly increased?
The grass population would decrease.
Why do we experience different seasons on Earth?
Because Earth is tilted as it revolves around the Sun.
A ball has a mass of 2 kg and accelerates at 3 m/s². What force acts on it?
6 N
Two identical plants are given the same amount of water and soil. Plant A receives sunlight, while Plant B is kept in darkness. After two weeks, Plant A grows better. What is the most reasonable conclusion?
Sunlight affects plant growth.