NAEP Science 4 — Questions and Answers
Question 1: Which organelle is responsible for packaging and shipping proteins to other parts of the cell or outside the cell?
- Mitochondria
- Ribosomes
- Golgi apparatus (Correct answer)
- Lysosomes
Correct answer: Golgi apparatus
The Golgi apparatus modifies, packages, and directs proteins received from the endoplasmic reticulum to their final destinations inside or outside the cell.
Question 2: Sound travels fastest through which medium?
- Vacuum
- Air at room temperature
- Water
- Steel (Correct answer)
Correct answer: Steel
Sound travels fastest through solids like steel (~5,100 m/s) because particles are closely packed and can transmit vibrations more efficiently than liquids or gases.
Question 3: A scientist observes that a particular island's bird population has much less genetic variation than the mainland population it descended from. This is most consistent with the:
- Hardy-Weinberg equilibrium
- Bottleneck or founder effect (Correct answer)
- Disruptive natural selection
- Gene flow from the mainland
Correct answer: Bottleneck or founder effect
The founder effect (a type of genetic bottleneck) occurs when a small group colonizes a new area, carrying only a subset of the original genetic diversity.
Question 4: Acid rain is primarily caused by which pair of pollutants reacting with water vapor in the atmosphere?
- Carbon monoxide and ozone
- Sulfur dioxide and nitrogen oxides (Correct answer)
- Methane and carbon dioxide
- Chlorofluorocarbons and ammonia
Correct answer: Sulfur dioxide and nitrogen oxides
SO₂ and NOₓ released from burning fossil fuels react with atmospheric water to form sulfuric and nitric acids, which fall as acid rain.
Question 5: An object's weight on the Moon is about one-sixth its weight on Earth. This difference is due to the Moon having:
- Less mass than Earth, so less gravitational pull (Correct answer)
- A thinner atmosphere
- A slower rotational speed
- A different chemical composition
Correct answer: Less mass than Earth, so less gravitational pull
Weight equals mass × gravitational acceleration (g); the Moon's smaller mass produces a surface gravity about 1/6 of Earth's, reducing the object's weight.
Question 6: Which of the following best describes how vaccines protect individuals from disease?
- They destroy pathogens on contact in the bloodstream
- They stimulate the immune system to produce memory cells before infection (Correct answer)
- They replace damaged white blood cells
- They increase body temperature to kill viruses
Correct answer: They stimulate the immune system to produce memory cells before infection
Vaccines introduce antigens that trigger an immune response, causing the body to produce memory B and T cells ready to respond quickly if the real pathogen appears.
Question 7: During an experiment, a student dissolves salt in water and then heats the solution. As water evaporates, the student observes salt crystals forming. This demonstrates which process?
- Sublimation
- Condensation
- Crystallization (Correct answer)
- Combustion
Correct answer: Crystallization
Crystallization occurs when a solvent evaporates and the dissolved solid (solute) comes out of solution and forms an ordered crystal structure.
NAEP Science 4
Which organelle is responsible for packaging and shipping proteins to other parts of the cell or outside the cell?