CAASPP Science 2 — Questions and Answers
Question 1: A student observes that a dropped ball accelerates downward and then hits the ground. Which force is primarily responsible for this acceleration?
- Friction
- Gravity (Correct answer)
- Magnetism
- Buoyancy
Correct answer: Gravity
Gravity is the attractive force between Earth and the ball that causes it to accelerate downward at approximately 9.8 m/s².
Question 2: During photosynthesis, plants convert light energy into chemical energy stored in which molecule?
- Oxygen
- Water
- Glucose (Correct answer)
- Carbon dioxide
Correct answer: Glucose
Plants use light energy to convert carbon dioxide and water into glucose (C₆H₁₂O₆), storing energy in its chemical bonds.
Question 3: Which of the following best describes a physical change?
- Iron rusting when exposed to oxygen
- Wood burning to produce ash and smoke
- Ice melting into liquid water (Correct answer)
- Baking soda reacting with vinegar to produce gas
Correct answer: Ice melting into liquid water
Melting ice is a physical change because only the state of matter changes; the chemical composition of water (H₂O) remains the same.
Question 4: The rock cycle describes how rocks change over time. Which process transforms igneous rock into sedimentary rock?
- Melting and cooling
- Heat and pressure
- Weathering, erosion, and compaction (Correct answer)
- Crystallization
Correct answer: Weathering, erosion, and compaction
Igneous rock is broken down by weathering and erosion into sediments, which are then compacted and cemented to form sedimentary rock.
Question 5: A food web shows the feeding relationships in an ecosystem. What happens to the population of rabbits if all the foxes are removed from the ecosystem?
- Rabbit population decreases due to less competition
- Rabbit population stays the same
- Rabbit population initially increases due to less predation (Correct answer)
- Rabbit population immediately decreases due to disease
Correct answer: Rabbit population initially increases due to less predation
Without fox predation, the rabbit population would initially increase rapidly, though this could later cause resource depletion and population crash.
Question 6: Which layer of Earth's structure is responsible for generating Earth's magnetic field?
- Crust
- Mantle
- Outer core (Correct answer)
- Inner core
Correct answer: Outer core
Earth's magnetic field is generated by the movement of molten iron and nickel in the liquid outer core, creating electric currents.
Question 7: A student tests the effect of sunlight on plant growth by growing two identical plants, one in sunlight and one in the dark. What is the independent variable in this experiment?
- Height of the plants
- Amount of water given to each plant
- Presence or absence of sunlight (Correct answer)
- Type of plant used
Correct answer: Presence or absence of sunlight
The independent variable is what the experimenter deliberately changes — in this case, the presence or absence of sunlight.
CAASPP Science 2
A student observes that a dropped ball accelerates downward and then hits the ground.
Which force is primarily responsible for this acceleration?