GED Science Practice Test

Life science — Chimpanzees and Bonobos:

Chimpanzees and bonobos have 99.9 percent of alleles that are similar. A comparison chart shows both species share the same animal type (primate), home continent (Africa), social structure (group leader), and closely related tool use.

1. What does the chart suggest about the relationship between chimpanzees and bonobos?

• A. They have vastly different muscular systems.
• B. They most likely shared a common ancestor.
• C. They share minimal genetic similarity.
• D. They most likely lack social organization.

Answer: B. Extremely high genetic similarity (99.9% of alleles) combined with shared physical, geographic, and behavioral traits is strong evidence the two species descended from a shared common ancestor.

Physical science — Soundproofing Investigation:

A musician tested six materials of varying thickness (0.2–2.54 cm) and density (0.45–2,700 kg/m³) for soundproofing a small box, recording the average noise reduction for each.

2. Which statement describes a solution for the error in this investigation?

• A. More trials should be performed.
• B. The materials should be the same thickness.
• C. The box should be larger.

Answer: B. The materials varied in both thickness and density at the same time, making it impossible to isolate density's effect on noise reduction — keeping thickness constant would control this confounding variable.

Evaluating research — Cell Phones and Cancer:

One study surveyed 593 frequent cell phone users and 1,368 nonusers about phone usage and cancer history (self-reported). A second study followed 420,000 people, some for over 20 years, using recorded medical data.

3. Which study's conclusion is more likely to be correct, and why?

• A. The larger study, because it used a longer follow-up and recorded data instead of self-reporting.
• B. The smaller study, because it directly compared frequent users to nonusers.
• C. The larger study is less reliable because it only ran for part of its data collection window.
• D. The smaller study, because it found a location-specific pattern in the data.

Answer: A. A much larger sample size, a longer follow-up period, and recorded (rather than self-reported, recall-biased) data all make a study's findings more reliable.

Physical science — Ideal Gas Law:

The ideal gas law states PV = nRT. A helium balloon rises and increases in size at higher altitudes until it pops.

4. Which condition explains this phenomenon?

• A. Air pressure is lower at higher altitudes.
• B. The upper atmosphere has a greater amount of gas than the lower atmosphere.
• C. Temperatures are colder at higher altitudes.
• D. Different layers of the atmosphere have their own gas constants.

Answer: A. As external air pressure decreases with altitude, the gas inside the balloon expands to equalize with the lower outside pressure — consistent with PV = nRT (as P decreases, V increases for a roughly constant amount of gas and temperature).

Math/data — Kneepad Failure Testing:

A manufacturer tested 100 kneepads under increasing force. Failures by force range: 130–134.99 N: 5; 135–139.99 N: 17; 140–144.99 N: 53; 145–149.99 N: 22; 150–154.99 N: 3.

5. What is the probability that a kneepad will require a force of 145 N or greater to fail?

• A. 22%
• B. 53%
• C. 25%
• D. 75%

Answer: C. Failures at 145 N or greater total 22 + 3 = 25 out of 100 kneepads tested, giving a probability of 25/100 = 25%.

Earth science — Earthquake Seismogram:

A seismogram from a 6.6-magnitude earthquake shows three wave types arriving at a station: P-waves, S-waves, and Rayleigh (surface) waves.

6. Which wave type causes the most damage to buildings during an earthquake like this one?

• A. Rayleigh waves, because they have the greatest amplitude.
• B. P-waves, because they arrive first.
• C. S-waves, because they take longer to arrive.
• D. P- and S-waves together, because of combined shaking.

Answer: A. Rayleigh (surface) waves typically have the largest amplitude and longest duration of shaking of the three wave types, making them the primary cause of structural damage — even though P-waves arrive first and S-waves arrive second.