GED Science Sample Questions and Explanations

A producer makes its own food by photosynthesis. In a food web, producers have arrows going out to the animals that eat them, but no arrows coming in from food. Grass is the only producer in this web.

Wrong choices

• Hawk: The hawk eats other animals, so it is a consumer.
• Snake: The snake eats frogs and mice, so it is a consumer.
• Grasshopper: The grasshopper eats grass, so it is a consumer.

In a chemical change, a new substance forms. Rust (iron oxide) is a new substance made when iron reacts with oxygen and water. Melting, boiling, and cutting are physical changes because the substance stays the same.

Wrong choices

• Paper being cut in half: Cutting paper changes only its size and shape. It is still paper.
• Water boiling: Boiling is a change of state from liquid to gas. It is still water.
• Ice melting: Melting is a change of state. The ice is still water, so it is a physical change.

Coal formed over millions of years from buried plant remains. Once we use it, it cannot be replaced in a human lifetime, so it is nonrenewable.

Wrong choices

• Trees: Trees can be replanted and regrow in a human lifetime, so they are renewable.
• Sunlight: Sunlight keeps arriving every day, so it is renewable.
• Wind: Wind keeps blowing, so it is renewable.

DNA (deoxyribonucleic acid) is found in chromosomes. Its sequence of bases holds the instructions (genes) for making proteins, which shape an organism's traits.

Wrong choices

• Glucose: Glucose is a sugar used for energy.
• Starch: Starch is a stored form of sugar in plants.
• Protein: Proteins are made by following DNA's instructions. They do not store the instructions.

1. Density = mass ÷ volume.
2. 60 ÷ 20 = 3 g/cm³.

Check: 3 × 20 = 60 grams.

Wrong choices

• 0.33 g/cm³: 0.33 comes from dividing the volume by the mass. Divide mass by volume.
• 40 g/cm³: 40 comes from subtracting 20 from 60.
• 1,200 g/cm³: 1,200 comes from multiplying 60 by 20.

Earth rotates (spins) on its axis about once every 24 hours. The side facing the Sun has day, and the side facing away has night.

Wrong choices

• Earth moving around the Sun: Earth's trip around the Sun takes one year. That gives us years, not days.
• The Moon blocking the Sun each evening: The Moon blocks the Sun only during a solar eclipse, which is rare.
• The Sun moving around Earth: The Sun does not move around Earth. It only seems to cross the sky because Earth spins.

A dominant allele shows its trait even when only one copy is present. Pp has one dominant P, so the flowers are purple. The recessive p is hidden.

Wrong choices

• White: White flowers appear only when a plant has two recessive alleles (pp).
• Half purple and half white: The dominant allele controls the whole trait. The flowers are not split.
• Pink: With complete dominance, the traits do not blend into pink.

In conduction, heat passes from particle to particle through direct contact. Metals are good conductors, so heat moves quickly from the hot end of the spoon to the handle.

Wrong choices

• Convection: Convection is heat carried by moving liquid or gas. The spoon is a solid.
• Evaporation: Evaporation is liquid turning into gas. It does not carry heat up a spoon.
• Radiation: Radiation is heat carried by waves, like sunlight. The heat here moved through the metal by contact.

In the carbon cycle, plants and algae take carbon dioxide out of the air during photosynthesis and store the carbon in sugars. Burning fuels, respiration, and volcanoes return carbon dioxide to the air.

Wrong choices

• Burning fossil fuels: Burning fossil fuels adds carbon dioxide to the air.
• Animal respiration: Animals breathe out carbon dioxide, so respiration adds it to the air.
• Volcanic eruptions: Volcanoes release carbon dioxide into the air.

Sweat is mostly water. When it evaporates (turns into vapor) from the skin, it carries heat away from the body. This helps keep the inside of the body near a normal temperature. Keeping inside conditions steady is called homeostasis.

Wrong choices

• To raise the body's temperature: Sweating does the opposite. It lowers body temperature.
• To remove extra oxygen from the blood: Oxygen is not removed by sweat. Extra carbon dioxide leaves the body through the lungs.
• To store water in the skin for later: Sweating releases water from the body. It does not store water.